Acoustic core and forming tool and method thereof

Abstract

An acoustic core may include a resonance unit array configured as a plurality of resonance unit groups. The resonance unit group may include a plurality of resonance units, and the plurality of resonance units may be configured as partition resonance units including convergent resonance units and divergent resonance units. The convergent resonance unit and the divergent resonance unit may be defined by a plurality of unit walls formed integrally with each other and a partition member formed integrally with the plurality of unit walls. The partition member may at least partially define the convergent resonance unit and the divergent resonance unit. The convergent resonance unit may define an upper resonance space defined by the partition member and the top surface of the resonance unit array. The divergent resonance unit may define a lower resonance space defined by the partition member and the bottom surface of the resonance unit array.

Description

[0001] Federally funded research

[0002] This invention was made with government support under Contract No. DTFAWA-15-A-80013 awarded by the Federal Aviation Administration (FAA) of the U.S. Department of Transportation. The government has certain rights in this invention. Technical Field

[0003] The present disclosure relates to acoustic cores for attenuating noise, such as noise from a turbine, in a liner, tools for forming the acoustic cores, and methods of forming the acoustic cores. Background Art

[0004] Acoustic liners can be used to suppress or attenuate sound waves. For example, acoustic liners are used to suppress or attenuate noise from turbines, such as turbofan engines, and noise from other devices, such as wind turbine blades. Improved acoustic liners and acoustic cores, including those that provide improved sound wave attenuation, and improved methods of forming acoustic liners and acoustic cores having improved sound wave attenuation would be welcome in the art. Summary of the invention

[0005] Aspects and advantages will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the presently disclosed subject matter.

[0006] In one aspect, the present disclosure includes an acoustic core. An exemplary acoustic core may include an array of resonance units. In some embodiments, the array of resonance units may be configured as a plurality of resonance unit groups. The resonance unit group may include a plurality of resonance units, and the plurality of resonance units are configured as partitioned resonance units including convergent resonance units and divergent resonance units. The convergent resonance unit and the divergent resonance unit may be defined by a plurality of unit walls formed integrally with each other and a partition member formed integrally with the plurality of unit walls. The partition member may at least partially define the convergent resonance unit and the divergent resonance unit. The convergent resonance unit may define an upper resonance space defined by the partition member and the top surface of the resonance unit array. The divergent resonance unit may define a lower resonance space defined by the partition member and the bottom surface of the resonance unit array. The present disclosure also includes an acoustic liner. An exemplary acoustic liner may include an acoustic core as described herein.

[0007] In another aspect, the present disclosure includes a method of making an acoustic core. An exemplary method may include determining a configuration of a tool assembly and / or a configuration of one or more forming tools used in the tool assembly using a tool assembly construction system. The method may additionally or alternatively include making one or more forming tools and / or assembling a tool assembly including one or more forming tools, and forming an acoustic core using the tool assembly including the one or more forming tools. The tool assembly and / or one or more forming tools may have a configuration determined at least in part based on the configuration determined for the acoustic core.

[0008] In yet another aspect, the present disclosure includes a tool assembly for forming an acoustic core. An exemplary tool assembly may include a plurality of forming tools. A corresponding forming tool in the plurality of forming tools may include a support member and a plurality of forming elements coupled to the support member. When the plurality of forming tools are operated in proximity to each other, a mold cavity at least partially defined by the plurality of forming elements may correspond to an acoustic core to be formed by the tool assembly.

[0009] In another aspect, the present disclosure includes a computer-readable medium having computer-executable instructions. When executed by a processor, the computer-executable instructions can be configured to cause the processor to perform any method described herein. As an example, an exemplary computer-readable medium may include computer-executable instructions that, when executed by a processor, cause the processor to perform the method currently disclosed herein.

[0010] These and other features, aspects and advantages will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments and, together with the description, serve to explain certain principles of the presently disclosed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A complete and enabling disclosure, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0012] Figure 1A schematically depicts a perspective, partially cut-away view of an exemplary turbine having an acoustic liner;

[0013] Figure 1B An aircraft equipped with a turbine having an acoustic liner is schematically depicted;

[0014] Figure 1C A wind turbine equipped with an acoustic liner is schematically depicted;

[0015] Figure 2 schematically depicts an isometric partial cutaway view of a portion of an exemplary acoustic liner;

[0016] Figures 3A-3CThe top, side, and bottom perspective views of the acoustic core are depicted, respectively;

[0017] Figure 4A and 4B schematically depicts an exemplary sound path through an aperture in a resonant unit;

[0018] Figure 5 schematically depicts the relationship between the resonant frequency of a resonant cell and the size of an aperture included in a partition or cell wall of the resonant cell;

[0019] Figures 6A-6C schematically depicts an exemplary side cross-sectional view of a resonant unit that may be included in an acoustic core;

[0020] Fig.6D and 6E Schematically depicts a cross-section of a resonant unit (e.g. Fig. 6A or 6C) of the resonance space of the partition member;

[0021] Figures 7A-7C schematically depicts an elevation view of an exemplary partition aperture defining a passage through a partition member or an exemplary wall aperture defining a passage through a cell wall of a resonant cell;

[0022] Fig.7D Schematically depicts the Figures 8A-8C A side cross-sectional view of an exemplary partition member for partitioning an aperture as shown in FIG.

[0023] Figures 8A-8D schematically depicting additional exemplary side cross-sectional views of partitions that intersect the resonance space of a resonance unit;

[0024] Figures 9A-9F schematically depict corresponding front and side cross-sectional views of additional exemplary partition members including partition apertures;

[0025] Fig. 10A schematically depicts a perspective view of an exemplary wall aperture defining a passage through a cell wall;

[0026] Figures 10B-10D schematically depicts an elevation view of an exemplary wall aperture defining a passage through a cell wall;

[0027] Fig.11 Additional exemplary orifice configurations are schematically depicted;

[0028] Fig. 12A and 12B schematically depicts an exemplary coupled resonant unit;

[0029] Figures 13A-13Hschematically depicting a side cross-sectional view of a corresponding additional exemplary resonant unit group;

[0030] Figures 14A-14F schematically depicts a top cross-sectional view of an exemplary array of resonant cells;

[0031] Figures 15A-15D schematically depicts a side cross-sectional view of an exemplary array of resonant cells;

[0032] Fig.16A and 16B schematically depicts a cross-sectional view of an exemplary acoustic core having a convex curved profile;

[0033] Fig. 16C schematically depicts a cross-sectional view of an exemplary acoustic core having a concave curved profile;

[0034] Fig.17A Schematically depicts a Fig.16A An exemplary resonant unit group in an acoustic core shown in;

[0035] Fig. 17B Schematically depicts a Fig. 16B An exemplary resonant unit group in an acoustic core shown in;

[0036] Fig. 17C Schematically depicts a Fig.16A Another exemplary resonant unit group in the acoustic core shown in;

[0037] Fig.17D Schematically depicts a Fig. 16B Another exemplary resonant unit group in the acoustic core shown in;

[0038] Fig.18 schematically depicts a perspective view of another exemplary resonant unit group;

[0039] Fig.19 schematically depicts additional exemplary polyhedral structures that may be included in the resonant unit array;

[0040] Figures 20A-20I schematically depicts an exemplary tool assembly for forming an acoustic core according to an exemplary embodiment;

[0041] Fig.21A Another exemplary acoustic core having a curved profile (e.g., using Figures 20A-20C A cross-sectional view of an acoustic core formed by an exemplary tool shown in FIG.

[0042] Fig. 21B and 21CThe diagrams corresponding to Fig.21A A cross-sectional view of an exemplary acoustic screen and an exemplary back panel of an exemplary acoustic core shown in FIG.

[0043] Fig.21D Schematic depiction of the use Fig.21A The acoustic core shown in Fig. 21B The acoustic screen and Fig. 21C A cross-sectional view of an exemplary acoustic liner formed by a backing plate shown in;

[0044] Fig.22A and 22B Flowcharts depicting exemplary methods of producing an acoustic core and / or an acoustic liner are shown, respectively; and

[0045] Fig.23 An exemplary acoustic core manufacturing system is schematically depicted.

[0046] Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present disclosure. DETAILED DESCRIPTION

[0047] Reference will now be made in detail to exemplary embodiments of the subject matter of the present disclosure, one or more examples of which are shown in the accompanying drawings. Each example is provided by way of illustration and should not be construed as limiting the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made to the present disclosure without departing from the scope of the present disclosure. For example, a feature shown or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, the present disclosure is intended to cover these modifications and variations that fall within the scope of the appended claims and their equivalents.

[0048] Acoustic liners for suppressing or attenuating sound waves, and methods for forming such acoustic liners are described herein. For example, acoustic liners can be used to suppress or attenuate noise generated or emitted by various aspects or components of a turbine, such as a turbofan engine used in an aircraft, including commercial, military, and civil aircraft. Acoustic liners can be used to suppress and attenuate noise from a variety of turbines, including turbojets, turbofans, turboprops, turboshafts, ramjets, pulsejets, turbines, gas turbines, steam turbines, marine engines, etc. In addition, or in an alternative, acoustic liners can be used to suppress or attenuate sound waves from other aircraft structures and / or wind turbine structures, including, for example, noise generated by fan blades, turbine blades, etc. Acoustic liners can be applied to the trailing edge, leading edge, or other places on the turbine blades of a wind turbine, the fan blades of any other turbine, and other rotating or stationary blades or other structures. More broadly, acoustic liners can be used to suppress or attenuate sound waves from any source that a person skilled in the art may think of.

[0049] The industry trend in aircraft turbine design is toward engines with higher and higher bypass ratios, for example, in an effort to reduce fuel consumption and emissions. Turbofan engines with higher bypass ratios tend to have dimensionally thinner, shorter nacelles, which reduces the volume available for acoustic linings for noise attenuation. In addition, the industry trend is toward turbofan engines with fewer fan blades and lower rotational speeds, which increases the proportion of lower frequency sound waves in the noise spectrum generated by the engine. Acoustic liners can benefit from relatively deep resonant cells so that the acoustic liner adequately attenuates the lower frequency sound waves. However, as engine designs continue to move toward higher and higher bypass ratios, fewer and fewer fan blades, and lower and lower rotational speeds, the space available for acoustic liners is increasingly limited. Similarly, core liners behind the turbine seek to attenuate relatively low frequency core noise in the relatively reduced volume available for the liner.

[0050] For wind turbines, industry trends are moving toward higher per-turbine energy capture, which corresponds to higher turbine diameters, for which maintaining lower rotational speeds for lower noise operation presents a design constraint that increases the cost of energy captured by the wind turbine. Acoustic linings can be added to wind turbine blades to achieve quieter noise levels during operation or to achieve higher tip speeds at a given noise level, thereby reducing the net system cost of wind turbine operation. However, the available space on wind turbine blades is also limited, which in turn limits the depth of the resonant cells and the corresponding attenuation of lower frequency sound waves. Wind turbine noise can be reduced below current levels by acoustically lining the blades in areas where turbulence effects dominate the observable noise radiation.

[0051] The presently disclosed acoustic liner includes an acoustic core having an array of resonant cells that can be configured, for example, to provide improved attenuation of low frequency sound waves. Additionally, or in the alternative, the array of resonant cells can be configured to attenuate a range of resonant frequencies, including low frequency sound waves, high frequency sound waves, and / or mid-frequency sound waves. The resonant cells within the array can include one or more cell walls and a resonant space defined by the one or more cell walls.

[0052] In some embodiments, the resonant frequency of a resonant unit can be lowered by providing one or more apertures in the unit wall and / or partitions of the resonant unit. It has been shown that such apertures introduce wave propagation that increases the wave propagation distance relative to the primary wave propagation mode along the axial length of the resonant space. As a result of such wave propagation, the resonant unit with the aperture can exhibit a lower resonant frequency. One or more apertures in the unit wall can define a passage between a previous resonant space and a subsequent resonant space of the corresponding resonant unit. One or more apertures in the partitions of the resonant unit can define a passage between an upper resonant space and a lower resonant space. One or more apertures provide a combined resonant space having an axial length including the resonant spaces on opposite sides of the aperture. In some embodiments, one or more apertures can be selectively configured to reduce the resonant frequency according to an aperture reduction factor so that the resonant length of the combined resonant space exceeds the height or axial length of such resonant space (see, for example, Figure 5 ).

[0053] A resonant cell having partitions that cross the resonant cell, with or without apertures defining a path through the partitions, may be referred to as a "partitioned resonant cell." An aperture in a cell wall may be referred to as a "wall aperture." An aperture in a partition may be referred to as a "partition aperture."

[0054] The resonant unit may be constructed as a vertical resonant unit or an inclined resonant unit. As used herein, the term "vertical resonant unit" refers to a resonant unit having a resonant space having a longitudinal axis following a path equidistant from the cell wall and locally perpendicular to the cell wall, wherein the longitudinal axis A has a vertical orientation relative to the top and / or bottom surface of the resonant unit. As used herein, the term "inclined resonant unit" refers to a resonant unit having a resonant space having a longitudinal axis A following a path equidistant from the cell wall and locally perpendicular to the cell wall, wherein the longitudinal axis has an inclined orientation relative to the top and / or bottom surface of the resonant unit. In some embodiments, the resonant frequency of the resonant unit may be reduced by orienting the resonant unit obliquely relative to the top and / or bottom surface of the acoustic core. The inclined resonant unit may include one or more partitioning members, so that the inclined resonant unit may be a partitioned resonant unit. Additionally or in an alternative, the inclined resonant unit may define a portion of the coupled resonant unit.

[0055] The array of resonant units may include one or more resonant unit groups. The term "resonant unit group" refers to a plurality of resonant units that are matched or grouped with each other in a recognizable pattern that is repeated over at least a portion of the array of resonant units. The recognizable pattern may include resonant units that are geometrically adapted to each other, and / or resonant units that are tuned to attenuate resonant frequencies in a complementary range. The resonant unit group may include one or more coupled resonant units. As used herein, the term "coupled resonant unit" refers to a resonant unit having an aperture in a unit wall adjacent to a previous resonant space and a subsequent resonant space. The resonant unit group may include one or more resonant units that reduce frequency, which may be a low frequency resonant unit, a high frequency resonant unit, and / or an intermediate frequency resonant unit. The coupled resonant unit may define a portion of a partitioned resonant unit.

[0056] As used herein, the term "reduced frequency resonant cell" refers to a resonant cell having one or more structures that reduce the resonant frequency of the resonant space of the cell compared to a corresponding nominal resonant cell. For example, a reduced frequency resonant cell may include a partition having one or more apertures that reduce the resonant frequency of the resonant space of the cell. Additionally, or in the alternative, when one or more apertures in the cell wall have an aperture reduction factor (e.g., an aperture reduction factor of 0 ≤ to < 1.0 (see, e.g., Figure 5 )), the coupled resonance unit may be a resonance unit that reduces the frequency. The resonance unit that reduces the frequency may be tuned to any desired resonance frequency. For example, the resonance unit that reduces the frequency may be a low frequency resonance unit, a high frequency resonance unit, or an intermediate frequency resonance unit.

[0057] The term "nominal resonant cell" refers to a resonant cell produced by modifying or eliminating one or more structures of the resonant cell to which the reduced resonant frequency is attributed. For example, a nominal resonant cell would be produced by eliminating a partition member containing one or more apertures from the resonant cell. Additionally, or in the alternative, a nominal resonant cell would be produced by reducing an aperture reduction factor of one or more apertures in the cell wall so as to eliminate the reduction in resonant frequency due to the one or more apertures in the cell wall, such as by reducing the aperture reduction factor to 0.0 (see, e.g., Figure 5 ).

[0058] The term "low-frequency resonance unit" refers to a resonance unit tuned to a resonance frequency having a corresponding resonance length exceeding the height or axial length of the resonance unit or the height of the acoustic core in which the low-frequency resonance unit is included. The term "high-frequency resonance unit" refers to a resonance unit in a resonance unit group that is tuned to a resonance frequency greater than a "low-frequency resonance unit" in the resonance unit group. The term "mid-frequency resonance unit" refers to a resonance unit in a resonance unit group that is tuned to a resonance frequency less than a high-frequency resonance unit in the resonance unit group and greater than a low-frequency resonance unit in the resonance unit group.

[0059] As used herein, the term "resonance length" with respect to a subject resonant unit refers to the axial length along the longitudinal axis of the resonant space of the nominal resonant unit, which will provide a resonant frequency corresponding to the resonant space of the subject resonant unit. For a resonant unit with a reduced frequency, the resonant length of the unit exceeds the height or axial length of the resonant space of the unit. For a nominal resonant unit, the axial length of the resonant space is equal to the resonant length. The longitudinal axis A of the resonant space generally refers to an axis that crosses the resonant space, which is equidistant from the cell wall defining the resonant space and is oriented in the direction of wave propagation through the resonant space. For example, a resonant space having a vertical orientation relative to the top and / or bottom surface of the resonant unit will have a longitudinal axis that is also oriented vertically relative to the top and / or bottom surface, while a resonant space having an oblique orientation relative to the top and / or bottom surface will have a longitudinal axis that has a corresponding oblique orientation relative to the top and / or bottom surface. For a curved or irregular resonant space (including a combined resonant space of coupled resonant units), the longitudinal axis A follows a path that is equidistant from the cell wall defining the resonant space and is locally perpendicular to the cell wall. As used herein, the term "axial length" with respect to a resonant unit or a resonant space refers to a distance L along a longitudinal axis A that follows a path that is equidistant from and locally perpendicular to the respective cell walls. As used herein, the term "height" with respect to a resonant unit, a resonant space, and / or an acoustic core refers to a distance along a normal that is oriented vertically or radially relative to the top and / or bottom surfaces. It should be understood that, depending on the configuration of the resonant unit, the resonant length of the resonant unit may be different from the axial length and / or height of the resonant unit.

[0060] The "resonance frequency" of a resonant unit refers to the frequency at which the absorption coefficient of the resonant unit is the largest. It should be understood that the exemplary frequency values ​​of the low-frequency, high-frequency and medium-frequency resonant units herein are provided as examples only and are not limiting. An exemplary low-frequency resonant unit can be tuned to a resonant frequency of, for example, from about 200 Hz to about 3,000 Hz (e.g., from about 250 Hz to about 2,000 Hz, or, for example, from about 200 Hz to about 1,500 Hz). A low-frequency resonant unit can be tuned to a resonant frequency of, for example, less than about 2,500 Hz (e.g., less than 2,000 Hz, such as less than 1,500 Hz, such as less than 1,000 Hz, or, for example, less than 500 Hz). A low-frequency resonant unit can be tuned to a resonant frequency of, for example, at least 250 Hz (e.g., at least 500 Hz, such as at least 1,000 Hz, such as at least 1,500 Hz, or, for example, at least 2,000 Hz).

[0061] An exemplary high frequency resonance unit may be tuned to a resonance frequency of, for example, from about 1,000 Hz to about 10,000 Hz (e.g., from about 1,000 Hz to about 6,000 Hz, e.g., from about 2,500 Hz to about 5,000 Hz, e.g., from about 3,000 Hz to about 4,500 Hz, or e.g., from about 4,000 Hz to 8,000 Hz). The high frequency resonance unit may be tuned to a resonance frequency of, for example, less than about 10,000 Hz (e.g., less than about 8,000 Hz, e.g., less than about 6,000 Hz, e.g., less than about 5,000 Hz, e.g., less than 4,500 Hz, e.g., less than 4,000 Hz, e.g., less than 3,000 Hz, or e.g., less than 2,500 Hz). The high frequency resonance unit may be tuned to a resonance frequency of, for example, at least 1,000 Hz, for example at least 2,000 Hz, for example at least 2,500 Hz, for example at least 3,000 Hz, for example at least 4,000 Hz, for example at least 4,500 Hz, for example at least 5,000 Hz, for example at least 6,000 Hz, or for example at least 8,000 Hz.

[0062] The exemplary intermediate frequency resonance unit can be tuned to a resonance frequency of, for example, from about 400 Hz to about 6,000 Hz (e.g., from about 1,000 Hz to about 4,000 Hz, such as from about 1,500 Hz to about 3,500 Hz, or, for example, from about 1,000 Hz to about 3,000 Hz). The intermediate frequency resonance unit can be tuned to a resonance frequency of, for example, less than about 6,000 Hz (e.g., less than about 4,000 Hz, such as less than 3,500 Hz, such as less than 3,000 Hz, such as less than 2,500 Hz, or, for example, less than 1,000 Hz). The intermediate frequency resonance unit can be tuned to a resonance frequency of, for example, at least 400 Hz (e.g., at least 1,000 Hz, such as at least 2,000 Hz, such as at least 2,500 Hz, such as at least 3,000 Hz, such as at least 3,500 Hz, such as at least 4,000 Hz, or, for example, at least 5,000 Hz).

[0063] In some embodiments, arrays of resonant cells may be produced using additive manufacturing techniques, which may allow for novel resonant cell configurations, geometries, and / or features described herein that may provide enhanced low frequency noise attenuation. For example, the use of additive manufacturing techniques may allow for the formation of resonant cells that reduce frequency, including coupled resonant cells and partitioned resonant cells. Adjacent resonant cells may share integrally formed cell walls with each other. Additionally, or in the alternative, partitions may be integrally formed with one or more cell walls. As used herein, the term "integrally formed" refers to the simultaneous formation of two or more features as part of the same process. For example, portions of an acoustic core or acoustic liner that are simultaneously formed using an additive manufacturing process are considered to be integrally formed. Portions of an acoustic core or acoustic liner that are first formed and then subsequently assembled or coupled to each other are not considered to be integrally formed. Although additive manufacturing techniques may be selected in some embodiments, it should be understood that the acoustic liner, acoustic core, and features thereof disclosed herein may be formed using other techniques, and reference to additive manufacturing techniques does not limit the scope of the present disclosure.

[0064] It should be understood that the terms "upstream" and "downstream" refer to the relative directions of the flow of fluid in a fluid passage. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction to which the fluid flows. It should also be understood that terms such as "top", "bottom", "outward", "inward", etc. are words of convenience and should not be interpreted as limiting terms. As used herein, the terms "first", "second", and "third" can be used interchangeably to distinguish one component from another, and are not intended to indicate the location or importance of a particular component. The terms "one" and "an" do not indicate a limitation of quantity, but rather indicate the presence of at least one of the referenced items.

[0065] Here and throughout the specification and claims, range limitations are combined and interchanged, and unless context or language indicates otherwise, such ranges are identified and include all sub-ranges contained therein. For example, all ranges disclosed herein include the endpoints, and the endpoints are independently combinable with each other.

[0066] As used throughout the specification and claims, approximating language is applied to modify any quantitative representation that can be permissibly varied without resulting in a change in the basic function to which it is related. Thus, values ​​modified by terms such as "about," "approximately," and "substantially" are not limited to the precise values ​​specified. In at least some cases, approximate language may correspond to the precision of an instrument used to measure a value, or the precision of a method or machine used to construct or manufacture a component and / or system. For example, approximate language may refer to within a 10% margin.

[0067] Exemplary embodiments of the present disclosure will now be described in more detail. Figure 1A As shown, one or more acoustic liners 100 may provide a system for suppressing or attenuating sound waves, including sound waves associated with turbine 102. Figure 1B In the exemplary embodiment shown, an aircraft 140 may include a turbine 102 (eg, a turbofan engine) wherein one or more acoustic liners 100 are configured to attenuate noise from the turbine 102. Figure 1C In another exemplary embodiment shown, a wind turbine 150 may include a turbine blade 152, wherein one or more acoustic liners 100 are applied to one or more portions of the turbine blade 152 to attenuate noise therefrom. For example, the acoustic liner may be applied to a leading edge region and / or a trailing edge region of a turbine blade 152 of the wind turbine 150.

[0068] Still refer to Figure 1A, the turbine 102 may include a casing or nacelle 104 surrounding a turbine 106 and / or a fan rotor 108, the fan rotor 108 including a plurality of circumferentially spaced fan blades 110 powered by the turbine 106. The exemplary casing or nacelle 104 includes an inlet 112 and a duct having a duct wall 114, the duct directing an airflow 116 downstream through the fan rotor 108 generally along a longitudinal axial centerline 118. The acoustic liner 100 provides a system for suppressing or attenuating sound waves. The exemplary system may include one or more acoustic liners 100 disposed annularly along the duct wall 114. The one or more acoustic liners 100 may have a location along the duct wall 114 upstream of the fan blades 110. The one or more acoustic liners may also be positioned downstream of the fan blades 110. For example, the acoustic liner may be positioned at or behind the inner barrel 120 portion of the nacelle 104. Additionally or alternatively, one or more acoustic liners 100 may be positioned at or behind the fan housing portion 122 and / or the rotor cover portion 124 of the nacelle 104. In some embodiments, the turbine 102 may include a plurality of housings 104 surrounding the turbine 106. In some embodiments, the plurality of housings 104 may be annularly constructed and arranged relative to each other. Each such housing 104 may include an inner duct wall 114 and an outer duct wall 114. One or more acoustic liners 100 may be positioned around the inner duct wall 114 and / or the outer duct wall 114 of any one or more of the plurality of housings 104. In addition, one or more acoustic liners 100 may be positioned near the non-rotating portion of the fan housing portion 122 or other components of the turbine 102. These locations include ducts or housings within the turbine 102, where acoustic liners may be used for noise suppression (e.g., damping or attenuation) of various frequency ranges (including a spectrum across the frequency range). For example, one or more acoustic liners 100 may be positioned at the core cover portion 126. Those skilled in the art will appreciate that the acoustic liner 100 may be positioned to suppress or attenuate further areas of noise generated or emitted by various aspects of the turbine 102 , all within the scope of the present disclosure.

[0069] In operation, the turbine 102 generates a large amount of noise. To illustrate an exemplary source of turbine 102 noise, it should be understood that the fan rotor 108 rotates within the fan housing portion 122, generating discrete tonal noise primarily at the blade pass frequency (BPF) and multiples thereof, as well as broadband noise over a wide frequency range. During takeoff of the aircraft 140, the fan blades 110 may reach transonic and supersonic rotational speeds, generating noise that propagates from the fan duct into the surrounding environment. In an exemplary embodiment, one or more acoustic liners 100 are constructed and arranged to suppress noise resonating at the BPF and harmonics of the BPF, as well as the main broadband noise contribution from the fan. One or more acoustic liners 100 or various portions thereof may be constructed to suppress or attenuate sound waves, thereby reducing sound at a specific frequency or across a frequency range. Some aspects of the acoustic liner 100 may be configured to reflect or propagate an incident sound wave multiple times before the sound wave leaves the acoustic liner 100. These multiple reflections may reduce the amplitude of the sound wave. Additionally, some aspects of the acoustic liner 100 may be configured to cause the sound waves to become out of phase due to such reflection or propagation. When the sound waves become out of phase, the various portions of the sound waves tend to cancel each other, thereby reducing at least some of the energy in the sound waves.

[0070] Figure 2 An isometric partial cutaway view of a portion of an exemplary acoustic liner 100 is shown. Figure 2 The acoustic liner 100 shown in FIG. 1 may be configured to Figure 1A 102, or for attenuating noise from any other source that may occur to one skilled in the art. In some embodiments, the acoustic liner 100 may be disposed in the airflow 116 (also in the Figures 1A-1C ) near the duct wall 114 and / or the fan housing portion 122. The acoustic liner 100 can be secured within the turbine 102 by flanges or other attachments to the duct wall 114 and / or the fan housing portion 122. The acoustic liner 100 includes an acoustic core 200 positioned between an acoustic shield 202 and a substantially imperforate back plate 204. The acoustic shield 202 may include a perforated plate, a mesh (e.g., formed of silk, cloth, fiber and / or filament), or a combination thereof. In addition, or in the alternative, the acoustic shield 202 may include an additively manufactured component. In some embodiments, the acoustic shield 202 and the back plate 204 form planes having a substantially parallel orientation relative to each other. The acoustic core 200 is composed of a hollow honeycomb structure or resonant unit 206 disposed between the acoustic shield 202 and the back plate 204. The resonant unit 206 includes a plurality of unit walls defining a hollow resonant space 208.

[0071] The acoustic core 200, the acoustic screen 202, the backing plate 204 may be formed separately from one another or simultaneously as part of an additive manufacturing technique or any other suitable process. The acoustic screen 202 and / or the backing plate 204 may additionally or alternatively be formed separately from the acoustic core 200 or simultaneously as part of any other manufacturing technique. Additionally or in the alternative, the acoustic screen 202 and / or the backing plate 204 may be bonded to the acoustic core 200, for example, using an adhesive process such as a heat, sonic wave, or electrical welding process. Alternatively, the acoustic screen 202 and / or the backing plate 204 may be secured to the acoustic core 200 using an adhesive formulation such as a thermosetting or pressure sensitive adhesive or adhesive tape.

[0072] The thickness or height of the acoustic core 200 can be determined by the axis R 214 (also Figure 1A The top surface 216 defines a first linear or curved surface of the acoustic core 200, and the bottom surface 218 defines a second linear or curved surface of the acoustic core 200. The top surface 216 is located near the inner surface of the acoustic screen 202 and is oriented toward the inner surface of the acoustic screen 202, and the bottom surface 218 is located near the inner surface of the back panel 204 and is oriented toward the inner surface of the back panel 204. Axis R 214 represents a normal relative to a normal surface corresponding to the top surface 216 and / or the bottom surface 218. Axis R can be radial or other axis determined by the context. In this exemplary embodiment, the terms "inner" and "outer" refer to the respective layers relative to each other. Figure 1A The orientation of the longitudinal axial centerline 118 is shown in .

[0073] The acoustic screen 202, backing plate 204 and acoustic core 200 may together form an arcuate or cylindrical profile (see, e.g., Figure 1A ), or linear or planar profiles (see e.g. Figure 2 ) of an acoustic liner 100. Of course, the acoustic liner may have any desired curved profile. For example, the acoustic liner 100 may surround a noise source, such as a fan blade 110 of a turbine 102. The acoustic screen 202 is oriented generally along the flow path to form a smooth and efficient path for engine flow, wherein the back panel 204 is further away from the noise source relative to the acoustic screen 202. As another example, an enclosed volume (such as a room or an engine casing) may contain a noise source (such as a noisy machine), and one or more walls or other aspects of such an enclosed volume may be lined with a substantially planar acoustic liner 100. In an exemplary embodiment, the acoustic core 200, the acoustic screen 202, and the back panel 204 may together form a complex curved acoustic liner 100, which, for example, may conform to a complex curved wall or other aspect of a cabin 104, or other room or space containing a noise source. For example, Figure 1AAn exemplary curved acoustic liner 100 is shown that conforms to the contours of a mounting location of a turbine 102 , such as a duct wall 114 , an inner barrel 120 , a fan case portion 122 , a rotor shroud portion 124 , a core shroud portion 126 , and / or a nacelle 104 .

[0074] In an exemplary embodiment, the acoustic core 200, the acoustic screen 202, and / or the backing plate 204 may be formed using additive manufacturing techniques, which may allow the acoustic liner 100 to have novel configurations, geometries, and / or features that provide certain improvements and / or avoid certain disadvantages compared to previous acoustic liners. Such additive manufacturing techniques may be used alone or in conjunction with other manufacturing techniques to provide an acoustic liner 100 according to the present disclosure.

[0075] For example, the acoustic liner 100 may be formed in whole or in part using additive manufacturing techniques. Sequential layers of the acoustic core 200, acoustic screen 202, and / or backing plate 204 may be additively manufactured using suitable additive manufacturing techniques. In an exemplary embodiment, the acoustic core 200, acoustic screen 202, and / or backing plate 204 may be additively manufactured in such a manner as to be one identical component without seams or the like separating the elements from one another.

[0076] Now turn to Figures 3A-3C , an exemplary acoustic core 200 will be described in more detail. As shown, the acoustic core 200 may include an array of resonant units 206. The resonant unit 206 may have a plurality of unit walls 300 bisected by a top surface 216 and a bottom surface 218. The resonant unit 206 may have any polyhedral structure or combination of structures, including vertical resonant units and / or tilted resonant units. The vertical resonant unit generally has a longitudinal axis that is perpendicular to the top surface 216 and / or the bottom surface 218, and / or substantially parallel to the normal 214 represented by the axis R. The tilted resonant unit has a resonant space 208, and the resonant space 208 has a longitudinal axis A that follows a path that is equidistant from the unit wall and locally perpendicular to the unit wall, wherein the longitudinal axis has an oblique orientation relative to the top surface 216 and / or the bottom surface 218. For a nominal resonant unit, the resonant length L of the resonant unit 206 can be determined from the bottom surface 218 to the top surface 216, as determined along the centerline of the resonant unit. A height H of the resonant unit 206 and / or the acoustic core 200 may be determined from the bottom surface 218 to the top surface 216 , as determined along the normal line 214 .

[0077] The tilted resonant unit can be tilted at a unit angle θ relative to the longitudinal axis A of the resonant space. C Tilt orientation. The tilted resonant unit can include a variety of unit angles θ ranging from greater than zero degrees to less than 90 degrees. CFor example, in an exemplary embodiment, the tilted resonance unit may have a unit angle θ from 5 degrees to 90 degrees (e.g., from 10 to 85 degrees, for example, from 20 to 80 degrees, for example, from 30 to 80 degrees, for example, from 40 to 80 degrees, for example, from 50 to 80 degrees, for example, from 60 to 80 degrees, for example, from 10 to 45 degrees, for example, from 45 to 80 degrees, for example, from 30 to 60 degrees, or for example, from 35 to 50 degrees). C . Unit angle θ C The unit angle θ may be greater than zero, such as at least 5 degrees, such as at least 10 degrees, such as at least 20 degrees, such as at least 30 degrees, such as at least 40 degrees, such as at least 50 degrees, such as at least 60 degrees, such as at least 70 degrees, such as at least 80 degrees. C It may be less than 90 degrees, such as less than 80 degrees, such as less than 70 degrees, such as less than 60 degrees, such as less than 50 degrees, such as less than 40 degrees, such as less than 30 degrees, such as less than 20 degrees, such as less than 15 degrees, such as less than 10 degrees, such as less than 5 degrees, or such as less than 1 degree. In contrast, the vertical resonant unit has a unit angle θ of 90 degrees. C .

[0078] Reference now Figure 4A and 4B , an example of sound wave propagation through one or more orifices will be described. In some embodiments, the sound wave propagation characteristics can be tuned to a desired frequency at least in part by the construction and arrangement of one or more orifices. An array of resonant cells tuned to attenuate lower frequency sound waves may include one or more orifices. A resonant cell that reduces frequency may include one or more orifices in a partition and / or cell wall 300. One or more orifices may help a resonant cell that reduces frequency exhibit a lower resonant frequency compared to a corresponding nominal resonant cell. For example, Figure 4A and 4B A partitioned resonant unit 600 is shown having a partition 402 that intersects the resonant space 208 and one or more apertures 404 that define corresponding one or more passages through the partition 402 .

[0079] like Figure 4A As shown, the aperture 404 has a position on the partition 402 that is aligned with the longitudinal axis 406 of the resonance space 208, which can be referred to as a central aperture 408. Figure 4BAs shown, the orifice 404 has a position on the partition 402 that is offset from the longitudinal axis 406 of the resonance space 208, which can be referred to as an offset orifice 410. The wave propagation distance of the sound wave propagating from the orifice 404 before contacting the cell wall 300 or the back plate 204 can be determined using the Pythagorean theorem. As shown, when the orifice 404 is offset from the longitudinal axis 406, the propagation distance of the sound wave propagating from the orifice 404 increases. As an illustration, the exemplary propagation path shows that for a given wave propagation angle, the wave propagation distance (D1, D2, and D3) of the offset orifice 410 exceeds the corresponding wave propagation distance (D1, D2, and D3) of the center orifice 408. In some embodiments, the sound wave propagating from the offset orifice 410 can exhibit enhanced reverberation within the resonance space 208 after propagating through the orifice 404.

[0080] Additionally, or in the alternative, the resonant frequency of the resonant unit 206 may be lowered by reducing the cross-sectional area of ​​the aperture 404 relative to the cross-sectional area of ​​the resonant unit. Figure 5 As shown, the resonant frequency has been shown to be dependent on the orifice reduction factor β. The resonant unit can be configured to present a resonant frequency selected using the following relationship based at least in part on the relationship between the orifice reduction factor β of the orifice and the resonant frequency of the resonant unit: a=c(1-β), where "a" is the cross-sectional dimension of the orifice 404, "c" is the cross-sectional dimension of the resonant space, and β is a real number selected from the following relationship: 0≤β<1.0. The cross-sectional dimension "a" of the orifice may include a cross-sectional area or a cross-sectional width. The cross-sectional dimension "c" of the resonant space may include a cross-sectional area or a cross-sectional width. In addition, or in the alternative, for a resonant unit including a plurality of orifices 404, the cross-sectional dimension "a" of the orifice 404 may include an open area percentage.

[0081] As will be appreciated by those skilled in the art, resonant frequency modeling (e.g., finite element analysis) can be used to determine the relationship between the aperture reduction factor β and the resonant frequency of a resonant unit construction. The relationship between the aperture reduction factor β and the resonant frequency of the resonant unit can then be used to construct a resonant unit having apertures 404 in partitions 402 that cross-section the resonant space of the resonant unit (e.g., partition apertures), and / or construct a resonant unit having apertures 404 in a unit wall (e.g., wall apertures). For example, such construction can include selecting a cross-sectional size for one or more apertures 404, selecting a cross-sectional size for one or more resonant spaces. Such cross-sectional sizes can be based at least in part on the aperture reduction factor β. In some embodiments, for example, Figure 5As shown, the relationship between the aperture reduction factor β and the resonant frequency of the resonant unit can include a resonant frequency that decreases as the aperture reduction factor β increases. As shown, the relationship can include linear and / or nonlinear regions. For example, an initial linear relationship can be transformed into a nonlinear relationship (e.g., an asymptotic relationship) as the aperture reduction factor β increases. Other relationships can also be apparent for various resonant unit configurations.

[0082] The resonant unit may be configured to have any suitable orifice reduction factor β between 0 and less than 1.0. In an exemplary embodiment, the orifice reduction factor β may be 0.2 to less than 1.0, such as 0.5 to less than 1.0, such as 0.7 to less than 1.0, such as 0.9 to less than 1.0, such as 0.3 to 0.8, such as from 0.6 to 0.99. The resonant unit may include an orifice 404 having an orifice reduction factor β of at least 0.1 (e.g., at least 0.3, such as at least 0.5, such as at least 0.7, or such as at least 0.9). The resonant unit may include an orifice 404 having an orifice reduction factor β of less than 1.0 (e.g., less than 0.95, such as less than 0.8, such as less than 0.6, or such as less than 0.4).

[0083] Now turn to Figures 6A-6E , an exemplary partitioning aperture 616 will be described in more detail. In some embodiments, the resonant unit 206 may include one or more partitioning elements 402 that transverse the resonant space 208 of the resonant unit 206. The acoustic core 200 may include an array of resonant units 206, wherein at least some of the resonant units are partitioned resonant units 600. The partitioning element 402 may transverse at least a portion of the resonant space 208, thereby demarcating an upper resonant space 602 from a lower resonant space 604. In some embodiments, the partitioning element 402 may be integrally formed with at least one of the one or more cell walls 300 that define the resonant space 208. For example, the resonant unit 206 including the cell wall 300 and the partitioning element 402 may be produced using additive manufacturing technology. Additionally, or in the alternative, the resonant unit 206 including the cell wall 300 and / or the partitioning element 402 may be formed using any other suitable technology.

[0084] The partition 402 may be formed at an interface angle θ determined from a plane parallel to the bottom surface 218 and / or the top surface 216 of the acoustic core 200. I The partition member 402 may include a surface having an interface angle θ parallel, inclined and / or perpendicular to the bottom surface 218 and / or top surface 216 of the corresponding resonant unit 206 and / or the array of resonant units 206. I .like Fig. 6A and 6CAs shown, the partition 402 can intersect the resonance space 208, wherein at least the first surface 606 of the partition 402 has an interface angle θ inclined relative to the bottom surface 218 and / or the top surface 216. I Additionally, or in the alternative, the partition 402 may intersect the resonance space 208, wherein at least the second surface 608 of the partition 402 has an interface angle θ parallel to the bottom surface 218 and / or the top surface 216. I For example, Fig. 6A and 6C As shown, the partition member may include an interface angle θ with respect to the bottom surface 218 and / or the top surface 216. I The first surface 606 has an interface angle θ parallel to the bottom surface 218 and / or the top surface 216. I The second surface 608. In some embodiments, for example, Figure 6B As shown, the partition 402 can have a relatively constant cross-sectional thickness.

[0085] In some embodiments, Fig.6D and 6E As shown, the partition 402 may include at least one support member 610 so that the partition 402 has a cross-sectional thickness at a region proximal to one or more cell walls 300 that exceeds the cross-sectional thickness of the partition 402 at a region distal to one or more cell walls. The partition 402 may include a cross-sectional thickness that transitions from a proximal cross-sectional thickness T1 612 at an interface with the cell wall 300 to a distal cross-sectional thickness T2 614 at a central region of the partition 402. The partition 402 may have a cross-sectional thickness that decreases from a proximal cross-sectional thickness T1 612 at an interface with the cell wall to a distal cross-sectional thickness T2 614 at a central region of the partition 402. As shown, the partition 402 may include a first surface 606 having an inclined interface angle θ oriented toward the back plate 204 and / or the bottom surface 218 of the resonant unit 206. I Additionally, or in the alternative, partition 402 can include a second surface 608 having an inclined interface angle θ oriented toward acoustic screen 202 and / or top surface 216 . I .

[0086] In some embodiments, Fig. 6A and 6C As shown, the partition member 402 may include a first surface 606 having an inclined interface angle θ oriented toward the back plate 204 and / or the bottom surface 218 of the resonant unit 206. I and a second surface 608 having a parallel interface angle θ oriented toward the acoustic screen 202 and / or the top surface 216 I Additionally, or in the alternative, such as Figure 6BAs shown, the partition member 402 may include a first surface 606 having an inclined interface angle θ oriented toward the back plate 204 and / or the bottom surface 218 of the resonant unit 206. I and a second surface 608 having an inclined interface angle θ oriented toward the acoustic screen 202 and / or the top surface 216 I .

[0087] like Figure 6B As shown, the acoustic screen 202 can be formed integrally with the array of resonant units 206. The acoustic screen 202 can interface with one or more unit walls 300 of the resonant unit 206 so that at least one surface of the acoustic screen 202 is inclined at an interface angle θ I The back plate 204 may intersect the resonant space 208. Additionally, or in the alternative, the back plate 204 may be integrally formed with the array of resonant units 206. The back plate 204 may interface with one or more cell walls 300 of the resonant units 206 such that at least one surface of the back plate 204 is at an inclined interface angle θ. I Transect the resonance space 208 .

[0088] In some embodiments, an additively manufactured acoustic core may include a partitioned resonant unit 600 having one or more partitions 402, wherein a surface 606 facing in a direction corresponding to a build plane of the additive manufacturing process is tilted at an interface angle θ I The partition 402 is transverse to the resonance space 208 of the resonance unit 206. Although the partition 402 is suspended from the resonance space 208 during the additive manufacturing process, the tilted interface angle θ I Additive manufacturing of partition 402 may be facilitated.

[0089] For example Fig. 6A and 6C As shown in FIG. 1 , when the array of resonant units 206 is additively manufactured from the bottom surface 218 to the top surface 216 (e.g., in a right-side-up orientation), the partition 402 can be integrally formed with one or more unit walls 300, and the partition 402 can include a surface 606 oriented toward the bottom surface 218, which is inclined at an interface angle θ I The resonant space 208 that crosses the resonant unit 206. In some embodiments, for example, Figure 6B As shown in FIG. 1 , an array of additively manufactured resonant units 206 may include partitions 402 having second surfaces 608 oriented toward top surface 216 at an inclined interface angle θ. I 208. Additionally, or in the alternative, an array of resonant cells 206 additively manufactured in a right-side-up orientation can include an integrally formed interface between an acoustic shield 202 and one or more cell walls 300, wherein a surface 607 of the acoustic shield 202 is oriented toward the bottom surface 218, the surface 607 being inclined at an interface angle θ I Transect the resonance space 208 .

[0090] When the array of resonant cells 206 is additively manufactured from the top surface 216 to the bottom surface 218 (e.g., oriented side-down), the partition 402 can be integrally formed with one or more cell walls 300, and the partition 402 can include a surface 606 oriented toward the top surface 216 at an inclined interface angle θ I The resonant space 208 of the resonant unit 206 is transverse. In some embodiments, the array of additively manufactured resonant units 206 may include a partition 402 having a second surface 608 oriented toward the bottom surface 218 at an inclined interface angle θ I 208. Additionally, or in the alternative, the array of resonant cells 206 additively manufactured in a side-down orientation can include an integrally formed interface between the back plate 204 and one or more cell walls, wherein a surface of the acoustic screen 202 is oriented toward the top surface 216, the surface being inclined at an interface angle θ I Transect the resonance space 208 .

[0091] Interface angle θ I The interface angle θ is determined from a plane parallel to the bottom surface 218 and / or the top surface 216 of the resonant unit array, and / or from a plane parallel to the back plate 204 and / or the acoustic screen 202 of the acoustic core 200. I θ may be selected for appropriate constructability of the overhanging feature using additive manufacturing techniques. However, in some embodiments, all interfaces between partitions 402 and cell walls 300 may be vertical. For example, for some additive manufacturing processes and / or for some resonant cell configurations, it may not be necessary to tilt the interface angle θ. I Additionally, or in the alternative, in some embodiments, the acoustic core 200 may be manufactured using any other suitable process.

[0092] like Fig. 6A As shown, the acoustic screen 202 and / or the back plate 204 may be attached to the array of resonant units 206. Additionally, or in the alternative, as Figure 6B and 6C As shown, the acoustic shield 202 and / or the back plate 204 can be at least partially formed integrally with the corresponding one or more cell walls 300 of the resonant unit 206 using additive manufacturing technology. The acoustic shield 202 and / or the back plate 204 can be produced using additive manufacturing technology, wherein the acoustic shield 202 and / or the back plate 204 are integrally formed with at least one of the corresponding one or more cell walls 300. In addition, or in the alternative, the cell walls 300, the acoustic shield 202, and / or the back plate 204 can be formed using any other suitable technology.

[0093] The array of resonant cells 206 may include partitions 402, acoustic screens 202, and / or back plates 204 that are arranged at any desired interface angle θ. I The slope of the partition 402, acoustic screen 202 and / or back panel 204 that crosses the resonant space 208 can be linear ( Fig.6D , 7A ) or curved ( Fig. 6E , 7B ). The partitions 402 throughout the array of resonant units 206 may have corresponding interface angles θ that are consistent or different from each other. I The respective portions of the acoustic screen 202 and / or the back plate 204 may be arranged at respective interface angles θ that are consistent or different from each other. I The corresponding resonance space 208 is transected.

[0094] For example, the interface angle θ I It can be from 5 to 90 degrees, such as from 10 to 85 degrees, such as from 20 to 80 degrees, such as from 30 to 80 degrees, such as from 40 to 80 degrees, such as from 50 to 80 degrees, such as from 60 to 80 degrees, such as from 10 to 45 degrees, such as from 45 to 80 degrees, such as from 30 to 60 degrees, or such as from 35 to 50 degrees. Interface angle θ I The interface angle θ may be greater than 0 degrees, such as at least 5 degrees, such as at least 10 degrees, such as at least 20 degrees, such as at least 30 degrees, such as at least 40 degrees, such as at least 50 degrees, such as at least 60 degrees, such as at least 70 degrees, such as at least 80 degrees. I It can be less than 90 degrees, for example less than 80 degrees, for example less than 70 degrees, for example less than 60 degrees, for example less than 50 degrees, for example less than 40 degrees, for example less than 30 degrees, for example less than 20 degrees, for example less than 15 degrees, for example less than 10 degrees, for example less than 5 degrees, or for example less than 1 degree.

[0095] like Figures 6A-6EAs further shown in FIG. 6 , in some embodiments, partition 402 may include one or more apertures defining a passage through partition 402, which may sometimes be referred to as partition apertures 616. An array of resonant units 206 may include at least some resonant units 206 having partitions 402, and at least some partitions 402 may include one or more partition apertures 616 defining a passage between upper resonant space 602 and lower resonant space 604. One or more partition apertures 616 may be formed in partition 402 during the additive manufacturing process by leaving uncured build material areas at selected locations of partition 402. Typically, when partition 402 is additively manufactured, the build material will cure in a manner that propagates inward from cell wall 300, such that partition 402 cantilever from cell wall 300. One or more partition apertures 616 may be constructed and arranged in a manner that allows partition 402 to be adequately supported by cell wall 300. Partition 402 may be formed in this manner with partition apertures 616 having various configurations and arrangements.

[0096] exist Figures 7A-7D , 8A-8D and 9A-9F show further exemplary partitioning elements 402 having partitioning apertures 616. In some embodiments, the partitioning element 402 may include a single partitioning aperture 616. Additionally, or in the alternative, the partitioning element 402 may include a plurality of partitioning apertures 616. Figures 7A-7D As shown, the partition aperture 616 can be centered between the cell walls 300 of the resonant cell 206. In addition, or in the alternative, the partition aperture 616 can be offset relative to the center point of the resonant cell 206, such as Figures 8A-8D The partition member 402 may include a single partition aperture 616 (eg Figures 7A-7D , Fig. 8A and 8B ), or a plurality of partitioned orifices 616 (eg Figure 8C , Fig.8D and Figures 9A-9F As shown). Compared to the partition aperture 616 centered on the partition element 402, the partition aperture 616 offset on the partition element 402 can reduce the build material while maintaining the appropriate buildability of the overhang feature using additive manufacturing techniques. In addition, or in the alternative, compared to the partition aperture 616 centered on the partition element 402, the partition aperture 616 offset on the partition element 402 can increase the wave propagation distance, which can enhance the attenuation of low frequency sound waves, as described above with reference to Figure 4A , Figure 4B and Figure 5 described.

[0097] like Fig. 7A As shown, the partition member 402 may have a partition opening 616 located at a middle position of the partition member 402 (eg, the center of the partition member 402). Figure 7B and 7C As shown, the partition member 402 can have a partition aperture 616 constructed and arranged in the form of a plurality of slots or grooves defined by respective portions of the partition member 402 cantilevered from one or more cell walls 300 . Fig.7D Shows Fig. 7A , 7B or an exemplary cross-sectional view of the partition aperture 616 of FIG. 7C showing the cantilevered portion of the partition member 402.

[0098] like Figures 9A-9F As shown, the partitioning element 402 may include a plurality of partitioning apertures 616. Any number of partitioning apertures 616 may be provided in the partitioning element 402 by carefully selecting a configuration and arrangement that allows the partitioning element 402 to be adequately supported by the cell wall 300. For example, Figure 7B and 7C as well as Fig.9A and 9B As shown, the partition 402 may include a plurality of cantilevered portions 618 extending from adjacent cell walls 300. The cantilevered portions 618 may be joined to each other at an intermediate position of the partition 402. Additionally, or in the alternative, the partition 402 may include a partition aperture array 620 defining an array of passages, such as Fig. 9C and 9D , Fig.9E and 9F The zoned aperture array 620 may have zoned apertures 616 configured and arranged in a uniform pattern or spacing, such as Fig. 9C and 9D Additionally, or in the alternative, the partitioned aperture array 620 may have partitioned apertures 616 constructed and arranged in a variety of shapes and / or sizes, such as Fig.9E and 9F shown.

[0099] Now turn to Figures 10A-10D In some embodiments, the array of resonant cells 206 may include one or more apertures 404 that define a passage through the cell wall 300. Such apertures 404 may sometimes be referred to as wall apertures 1000. In various embodiments, the wall apertures 1000 may span all or a portion of the cell wall 300, for example Fig. 10B As shown, one or more cell walls 300 or portions thereof may define the perimeter of a wall aperture 1000. Additionally, or in the alternative, the wall aperture may include one or more aperture walls 1002, such as Fig. 10C and 10DAs shown. One or more orifice walls 1002 may define a plurality of wall orifices 1000 therebetween. One or more orifice walls 1002 may be integrally formed with adjacent cell walls 300 using additive manufacturing techniques and / or any other suitable techniques. Any number of wall orifices 1000 may be provided in the cell walls 300 and / or between the orifice walls 1002 by carefully selecting a configuration and arrangement that allows the orifice walls 1002 to be adequately supported and the orifice walls 1002 to adequately support the cell walls 300. The orifice walls 1002 and corresponding wall orifices 1000 may be provided in a variety of configurations and arrangements, including but not limited to the orifices 404 described above with reference to the partitioned orifices 616.

[0100] The wall apertures of the corresponding resonant spaces of the adjacent resonant units (coupled resonant units) may be configured as resonant units that reduce the frequency. In an exemplary embodiment, the wall apertures 1000 may be positioned at offset positions in the unit wall 300, similar to the offset partition apertures 616, as described above with reference to Figure 4A , 4B as well as Figure 5 For example, the wall opening 1000 may be located at an offset position in the cell wall 300, such as near the bottom surface 218 and / or near the back panel 204, as shown in FIG. Figures 10A-10D The target resonant frequency of the coupled resonant unit may also be selected based at least in part on the size of the wall aperture 1000 according to the aperture reduction factor relationship: a=c(1-β).

[0101] Fig.11 Several further exemplary configurations and arrangements of the orifice 404 are shown, any one or more of which may be incorporated into the partition 402, the cell wall 300, and / or the orifice wall 1002. As shown, exemplary embodiments may include orifices 404 having polyhedral and / or elliptical cross-sectional shapes. For example, embodiments (a), (c), and (e) include polyhedral orifices 404, and embodiments (b), (d), and (f) include elliptical orifices 404. More specifically, embodiment (e) includes a rectangular orifice 404; embodiment (a) includes a teardrop orifice 404; embodiment (c) includes a hexagonal orifice 404; embodiments (b) and (c) include an elongated orifice 404; and embodiments (d) and (f) include a circular orifice 404. It should be understood that combinations of polyhedral and / or elliptical path orifices 404 are also within the scope of the present disclosure. In some embodiments, the orifices 404 may be oriented in an array or a staggered array. For example, as shown in embodiment (d), adjacent apertures 404 may be oriented in a vertical direction at unequal distances from each other.Apertures 404 may be arranged about partitions 402, cell walls 300, and / or aperture walls 1002 in any desired orientation, including ordered or random or semi-random orientations.

[0102] Now turn to Fig. 12A and 12B, an exemplary resonant unit group 1200 will be described. As shown, the resonant unit group may include at least one coupled resonant unit 1202 matched or grouped with one or more complementary resonant units 206, such as a high frequency resonant unit and / or a medium frequency resonant unit. The coupled resonant unit 1202 and / or the complementary resonant unit 206 in the resonant unit group 1200 may be configured as a resonant unit that reduces the frequency. As shown, the coupled resonant unit 1202 may include at least one unit wall 300 having one or more apertures 404 (e.g., wall apertures 1000) defining a passage between the previous resonant space 1204 and the subsequent resonant space 1206. The previous resonant space 1204 and the subsequent resonant space 1206 may sometimes be collectively referred to as a coupled resonant space 1208. In some embodiments, the coupled resonant space 1208 may exhibit a relatively low resonant frequency. The coupled resonant unit 1202 may be configured to attenuate any desired resonant frequency. In an exemplary embodiment, the coupled resonant unit 1202 may be configured to attenuate a relatively low resonant frequency. The coupled resonant unit 1202 may be configured as a low frequency resonant unit. The coupled resonant unit 1202 may have a resonant length that exceeds the height or axial length of the coupled resonant unit 1202 and / or the height of the acoustic core 200 including the coupled resonant unit 1202 .

[0103] like Fig. 12A and 12B As shown, in some embodiments, the coupled resonance unit 1202 may include a partition 402 that crosses at least a portion of the resonance space 208. For example, the partition 402 may define an upper resonance space 602 and a lower resonance space 604. The lower resonance space 604 may define at least a portion of the coupled resonance space 1208. The upper resonance space 602 may exhibit a relatively high resonance frequency. The lower resonance space 604 and / or the coupled resonance space 1208 may exhibit a relatively low resonance frequency. Fig. 12A As shown, in some embodiments, the resonant unit group 1200 may include a coupled resonant space 1208 grouped or matched with a resonant space 208 having a relatively high resonant frequency (e.g., an upper resonant space 602 on the opposite side of the partition member 402). In addition, or in an alternative, as Fig. 12BAs shown, the resonance unit group 1200 may include one or more intermediate frequency resonance units 1210 that respectively define intermediate resonance spaces 1212. As shown, the intermediate frequency resonance unit may be at least partially adjacent to at least one coupled resonance unit 1202 and / or at least partially surrounded by at least one coupled resonance unit 1202. The intermediate frequency resonance unit may share one or more unit walls 300 with the previous resonance space 1204 and / or the subsequent resonance space of the coupled resonance unit 1202. The intermediate frequency resonance unit may exhibit a relatively medium resonance frequency. When the resonance unit group 1200 includes the intermediate frequency resonance unit 1210, the coupled resonance space 1208 may include an intermediate resonance space 1214 disposed between the previous resonance space 1204 and the subsequent resonance space 1206. For example, as Fig. 12B As shown, the intermediate resonance space 1214 can be close to the bottom surface 218 of the array of resonance units 206, for example, between the intermediate frequency resonance unit 1210 and the back plate 204 of the acoustic core 200. Fig. 12B As shown, the passage between the previous resonance space 1204 and the subsequent resonance space 1206 can cross the intermediate frequency resonance unit 1210. The intermediate frequency resonance unit 1210 can include a partition 402 that separates the passage from the intermediate resonance space 1212. The partition 402 that separates the passage from the intermediate resonance space 1212 can define an intermediate resonance space 1214, and the intermediate resonance space 1214 can define at least a portion of the passage between the previous resonance space 1204 and the subsequent resonance space 1206. In some embodiments, the partition 402 can be perpendicular to one or more cell walls 300 of the resonance unit group 1200.

[0104] For example, Fig. 12A As shown, the longitudinal axis A of the coupled resonant cell 1202 follows a path that is equidistant from and partially perpendicular to the cell walls 300 that define the preceding resonant space 1204 and the subsequent resonant space 1206 of the coupled resonant cell 1202. For example, Fig. 12B As shown, the axial length L of the coupled resonant unit 1202 can extend along the longitudinal axis A from the top surface 216 defining the previous resonant space 1204 to the partition member 402 defining the subsequent resonant space 1206, and the longitudinal axis A is equidistant from the corresponding unit wall 300 and locally perpendicular to the corresponding unit wall 300. In an exemplary embodiment, the cross-sectional dimension "a" of the wall aperture 1000 defining the passage between the previous resonant space 1204 and the subsequent resonant space 1206 can be smaller than the cross-sectional dimension "c1" of the previous resonant space 1204. In addition, or in the alternative, the cross-sectional dimension "a" of the wall aperture 1000 can be smaller than the cross-sectional dimension "c2" of the subsequent resonant space 1206. The cross-sectional dimension "c1" of the previous resonant space 1204 and / or the cross-sectional dimension "c2" of the subsequent resonant space 1206 can be determined adjacent to more wall apertures 1000. As shown in FIG. Fig. 12B As shown, when the resonance unit group 1200 includes the intermediate frequency resonance unit 1210 , the corresponding coupling resonance unit 1202 may include an intermediate resonance space 1214 .

[0105] The cross-sectional dimension “a1” of the wall opening 1000 and / or the intermediate resonance space 1214 adjacent to the previous resonance space 1204 may be smaller than the cross-sectional dimension “c1” of the previous resonance space 1204. l In addition, or in the alternative, the cross-sectional dimension “a2” of the wall aperture 1000 and / or the intermediate resonant space 1214 adjacent to the subsequent resonant space 1206 may be smaller than the cross-sectional dimension “c2” of the subsequent resonant space 1206 .

[0106] The cross-sectional dimensions of one or more wall apertures 1000 defining a passage between the previous resonant space 1204 and the subsequent resonant space 1206 may be determined at least in part based on the aperture reduction factor β. Additionally, or in the alternative, the cross-sectional dimension “c1” of the previous resonant space 1204 and / or the cross-sectional dimension “c2” of the subsequent resonant space 1206 may be determined at least in part based on the aperture reduction factor β. The aperture reduction factor β may be determined at least in part based on the relationship between the aperture reduction factor β and the resonant frequency of the resonant unit.

[0107] Now turn to Figures 13A-13H In some embodiments, the array of resonant units 206 may include a tilted resonant unit 1300. Additionally or alternatively, the array of resonant units 1200 may include a tilted resonant unit 1300. The tilted resonant unit 1300 may include at least one surface that is oriented obliquely relative to the top surface 216 and / or the bottom surface 218. Additionally or alternatively, the tilted resonant unit 1300 may include at least one surface that may be oriented vertically relative to the top surface 216 and / or the bottom surface 218. The tilted resonant unit 1300 may be configured as a resonant unit that reduces the frequency. In some embodiments, as Figures 13A-13H As shown, the tilted resonant unit 1300 can provide a longer resonant length for a given acoustic core 200 height compared to a resonant unit 206 having a unit wall 300 oriented vertically or radially relative to the bottom surface 218 or the top surface 216 of the acoustic core 200. The tilted resonant unit 1300 can be configured as a low-frequency resonant unit. The tilted resonant unit 1300 can exhibit a resonant length that exceeds the height or axial length of the tilted resonant unit 1300 and / or the height of the acoustic core 200 including the tilted resonant unit 1300. Figures 13A-13H The longitudinal axis A of the previous resonant space 1204 is shown. The longitudinal axis A of the coupled resonant space 1208 will extend through the previous resonant space 1204 and the coupled resonant space 1208, for example Fig. 12A shown.

[0108] For example, Fig.13A and 13B As shown, the inclined resonance unit 1300 can be constructed and arranged to couple the resonance unit 1202, thereby providing a coupled resonance space 1208 with a relatively low resonance frequency. As shown, the coupled resonance space 1208 can be cross-sectioned by a partition 402. The partition 402 that crosses the coupled resonance space 1208 can demarcate the high-frequency resonance unit 1302 that defines the high-frequency resonance space 1304. The resonance unit group 1200 may include a coupled resonance unit 1202 grouped or matched with the high-frequency resonance unit 1302. In some embodiments, as Fig. 13B As shown, the partition member 402 may include one or more partition apertures 616 that define a passage between the coupling resonant space 1208 and the high frequency resonant space 1304, thereby allowing acoustic interaction therebetween.

[0109] In some embodiments, the partitioning element 402 can be perpendicular to one or more cell walls 300 of the resonant cell group 1200. For example, the partitioning element 402 can be perpendicular to one or more cell walls 300 of the tilted resonant cell 1300. In addition, or in the alternative, the partitioning element 402 can be perpendicular to the longitudinal axis A of the resonant space 208 at a cell angle θ. C The cell wall 300 of the tilted resonant cell 206 is oriented. For example, the partition member 402 can be perpendicular to the cell angle θ of from 5 to 90 degrees (e.g., from 10 to 85 degrees, such as from 20 to 80 degrees, such as from 30 to 80 degrees, such as from 40 to 80 degrees, such as from 50 to 80 degrees, such as from 60 to 80 degrees, such as from 10 to 45 degrees, such as from 45 to 80 degrees, such as from 30 to 60 degrees, or such as from 35 to 50 degrees). C The cell wall 300. The cell angle θ C It may be greater than 0 degrees, such as at least 5 degrees, such as at least 10 degrees, such as at least 20 degrees, such as at least 30 degrees, such as at least 40 degrees, such as at least 50 degrees, such as at least 60 degrees, such as at least 70 degrees, such as at least 80 degrees. Unit angle θ C It may be less than 90 degrees, such as less than 80 degrees, such as less than 70 degrees, such as less than 60 degrees, such as less than 50 degrees, such as less than 40 degrees, such as less than 30 degrees, such as less than 20 degrees, such as less than 15 degrees, such as less than 10 degrees, such as less than 5 degrees, or such as less than 1 degree. In contrast, the vertical resonant unit has a unit angle θ of 90 degrees. C .

[0110] like Figures 13C-13FAs shown, in some embodiments, the array of resonance units 206 may include one or more coupled resonance units 1202 matched with one or more intermediate frequency resonance units 1210 and / or one or more high frequency resonance units 1302. The intermediate frequency resonance unit 1210 may include a partition 402 that separates a passage 1305 from an intermediate resonance space 1212. The intermediate frequency resonance unit 1210 may define an intermediate resonance space 1212, and the high frequency resonance unit 1302 may define a high frequency resonance space 1304. The intermediate resonance space 1212 may have a resonance frequency greater than the resonance frequency of the coupled resonance space 1208 and / or less than the resonance frequency of the high frequency resonance space 1304. In some embodiments, for example, as Fig.13D and 13E As shown, the intermediate frequency resonance unit 1210 may include a partition member 402 that defines an upper resonance space 602 and a lower resonance space 604. Fig.13D As shown, the partition member 402 may include one or more partition apertures 616 that define a passage between the upper resonant space 602 and the lower resonant space 604 .

[0111] In some embodiments, for example, Fig.13F As shown, the plurality of coupled resonant units 1202 may define corresponding previous resonant spaces 1204 in the plurality of previous resonant spaces 1204 that converge into the subsequent resonant space 1206. For example, the first wall aperture 1000 may define a passage between the first previous resonant space 1204 and the subsequent resonant space, and the second wall aperture 1000 may define a passage between the second previous resonant space 1204 and the subsequent resonant space 1206.

[0112] Now turn to Figure 13G and 13HIn some embodiments, the resonant unit group 1200 may include one or more converging resonant units 1306 and / or one or more diverging resonant units 1308. The converging resonant unit includes one or more unit walls 300 that converge with each other, such that the top surface 216 of the resonant unit 206 has a larger cross-sectional area than the bottom surface 218 of the resonant unit. The diverging resonant unit 1308 includes one or more unit walls 300 that diverge relative to each other, such that the top surface 216 of the resonant unit has a smaller cross-sectional area than the bottom surface 218 of the resonant unit 206. The converging resonant unit 1306 and / or the diverging resonant unit 1308 may be described by a convergence ratio, which refers to the ratio of the cross-sectional area of ​​the top surface 216 of the resonant unit 206 to the cross-sectional area of ​​the bottom surface 218 of the resonant unit 206. The converging resonant unit 1306 has a convergence ratio greater than 1.0, while the diverging resonant unit 1308 has a divergence ratio less than 1.0. In some embodiments, the resonant frequency of the resonant unit 206 can depend at least in part on the convergence ratio of the resonant unit 206. The convergence ratio of the resonant unit 206 can be selected based at least in part on the desired resonant frequency resulting from the convergence ratio. Additionally, or in the alternative, in some embodiments, the convergence ratio can be selected based at least in part on the desired curvature of the resonant unit 206, the resonant unit group 1200, and / or the acoustic core 200 resulting from the convergence ratio, such as in the case of a curved or complex curved acoustic core 200. For example, a curved acoustic liner 100 (see, e.g., Figure 1A ) may include an acoustic core 200 having at least some converging resonance units 1306 and / or at least some diverging resonance units 1308. Additionally or in the alternative, the converging resonance units 1306 and / or the diverging resonance units 1308 may have a plurality of converging resonance units 1306 and / or a plurality of diverging resonance units 1308 based at least in part on the unit angle θ. C The desired resonant frequency produced, and / or the unit angle θ selected based at least in part on the desired curvature of the resonant unit 206, the resonant unit group 1200, and / or the acoustic core 200 produced by the convergence ratio C The resonant frequency of the resonant unit 206 may depend on the convergence ratio and the unit angle θ C combination.

[0113] like Figure 13G As shown, in some embodiments, the resonance unit group 1200 may include one or more intermediate frequency resonance units 1210 located between the coupled resonance units 1202. In some embodiments, the intermediate frequency resonance unit 1210 may have one or more unit walls 300 that converge and / or abut each other. Figure 13G As shown, one or more cell walls 300 may abut at an aperture wall 1002 defining a wall aperture 1000 .

[0114] It should be understood that any combination of resonance units 206 can be provided, which includes any one or more features described herein and their combinations. For example, any combination of complementary resonance units 206 can be provided according to the present disclosure, including any combination of high-frequency resonance units 1302, intermediate frequency resonance units 1210 and / or low-frequency resonance units (e.g., coupled resonance units 1202, tilted resonance units 1300, etc.). In addition, the coupled resonance unit 1202 and the tilted resonance unit 1300 may include any combination of high-frequency resonance units 1302, intermediate frequency resonance units 1210 and / or low-frequency resonance units. In some embodiments, the resonance unit group 1200 may include two, three, four, five or more resonance units 206 having different configurations from each other. In addition, or in the alternative, the resonance unit group 1200 may include multiple resonance unit subgroups. For example, a first subgroup may include a first group of complementary resonance units and a second group of complementary resonance units, wherein the first group of complementary resonance units is complementary to the second group of complementary resonance units. As an example, a first group of complementary resonance units may include a high frequency resonance unit 1302, an intermediate frequency resonance unit 1210, and / or a low frequency resonance unit (e.g., a coupled resonance unit 1202, a tilted resonance unit 1300, etc.) that are matched or grouped with each other, so as to define a first resonance unit group or a first resonance unit subgroup. A second group of complementary resonance units may include a high frequency resonance unit 1302, an intermediate frequency resonance unit 1210, and / or a low frequency resonance unit (e.g., a coupled resonance unit 1202, a tilted resonance unit 1300, etc.) that are matched or grouped with each other, so as to define a second resonance unit group or a second resonance unit subgroup. At least some of the resonance units in the first resonance unit group or subgroup may be different from the corresponding resonance units in the second resonance unit group or subgroup. For example, the first high frequency resonating unit 1302 in the first resonating unit group or subgroup may be different from the second high frequency resonating unit 1302 in the second resonating unit group or subgroup, and / or the first intermediate frequency resonating unit 1210 in the first resonating unit group or subgroup may be different from the second intermediate frequency resonating unit 1210 in the second resonating unit group or subgroup, and / or the first low frequency resonating unit in the first resonating unit group or subgroup may be different from the second low frequency resonating unit in the second resonating unit group or subgroup. Thus, the resonating unit group 1200 may include any combination of resonating units 206 that provide the desired acoustic treatment.

[0115] Now turn to Figures 14A-14C, an exemplary construction of the array of resonant units 206 will be further described. When the array of resonant units 206 is additively manufactured, in some embodiments, the manufacturability and / or build quality can be enhanced by constructing the resonant units 206, the cell walls 300, and / or the partitions 402 aligned with each other so that the contour path followed by the additive manufacturing energy beam and / or the additive manufacturing tool extends through at least some adjacent resonant units 206. For example, the array of resonant units 206 may include one or more cell walls 300 aligned along a linear or curved track extending through a plurality of resonant units 206. In addition, or in an alternative, the array of resonant units may include one or more partitions 402 aligned along a linear or curved track extending through a plurality of resonant units 206. Such alignment may allow the additive manufacturing energy beam and / or tool to maintain continuous operation while passing through adjacent cell walls 300 and / or adjacent partitions 402. Such continuous operation may provide improved integration between adjacent cell walls 300, between adjacent partitions 402, and / or between cell walls 300 and partitions 402. In addition, such alignment can allow for reduced manufacturing time by reducing transition times between separate contour paths. However, such alignment between the resonant unit 206, the unit wall 300, and / or the partitioning element 402 is described as an example and is not intended to be limiting. In fact, other configurations and methods of operation are also conceivable, including partitioning elements 402 and / or unit walls 300 with staggered, patterned, or random orientations.

[0116] As an example, Figures 14A-14F 206. As shown, the exemplary resonant units 206 can be aligned with each other in the x-direction and / or the y-direction. Such alignment of the resonant units 206 can allow the unit walls 300 of adjacent resonant units 206 to be formed integrally with each other, e.g., to have interconnected contours. For example, a continuous unit wall 300 can extend through a plurality of resonant units 206. The unit wall 300 can present a linear cross-section ( Figures 14A-14C ) or curved cross section ( Figures 14D-14F The cross-section of the cell wall 300 may be determined along a curve parallel to the top surface 216 and / or the bottom surface 218 of the resonant cell. The cell wall 300 may form a grid in which the resonant cell 206 has a uniform cross-sectional area ( Fig.14A , 14D ) or uneven cross-sectional area ( Fig. 14B , 14C , 14E, 14F). The cross-sectional area of ​​at least some of the resonant units 206 in the array may include partitions 402. The resonant units 206 including partitions 402 may be staggered or offset relative to each other in the x-direction and / or the y-direction. For example, Fig.14AA plurality of partitioned resonant cells 600 are shown staggered or offset relative to each other. As shown, the partitioned resonant cells 600 may include first partitioned resonant cells 1400 staggered or offset with second partitioned resonant cells 1402 by at least one adjacent resonant cell 206. The staggering or offsetting may form a pattern, such as an alternating pattern.

[0117] Additionally, or in the alternative, at least some of the partitioned resonant units 600 may be aligned with each other in the x-direction and / or the y-direction. Figures 14B-14F An exemplary array of resonance units 206 is shown, which includes a plurality of partitioned resonance units 600 aligned with each other. As shown, the partitioned resonance unit 600 may include a third partitioned resonance unit 1404 aligned with a fourth partitioned resonance unit 1406. As an example, the partitioned resonance units 600 may be aligned in rows or columns.

[0118] In some embodiments, for example, Fig. 14C As shown, the array of resonant cells 206 may include a first plurality of partitioned resonant cells 1408 that are staggered or offset from a second plurality of partitioned resonant cells 1410. The first plurality of partitioned resonant cells 1408 may follow an irregular path, and / or the second plurality of partitioned resonant cells 1410 may follow an irregular path.

[0119] Reference now Figures 15A-15D , shows a side cross-sectional view of an exemplary array of resonant units 206. As shown, the array of resonant units 206 may include partitioned resonant units 600 (e.g., Fig.15A ), and / or partitioned resonant units 600 staggered relative to each other in the z direction (e.g., Fig. 15B ). In some embodiments, Figures 15A-15D The partitioned resonant unit 600 shown in the figure may include an aperture 404, which includes a partition aperture 616 and / or a wall aperture 1000. When at least partially aligned in the z-direction, the partition element 402 and the cell wall 300 can be formed integrally with each other, for example, with interconnected contours. This z-direction alignment can allow an uninterrupted contour path across adjacent partition elements 402 and / or across adjacent cell walls 300, which can provide full integration between adjacent cell walls 300, between cell walls 300 and partition elements 402, and / or between adjacent partition elements 402. In addition, this alignment can allow for reduced manufacturing time and improved integration between cell walls and partition elements by reducing transition time between separate contour paths.

[0120] The z-direction position of the partition 402 may be selected, for example, to tune the corresponding resonance space to a desired resonance frequency. Fig.15AAs shown, the plurality of partitioned resonant units 600 may have partition members 402 at least partially located at a common z-direction position, so that the plurality of partitioned resonant units 600 may be tuned to a common resonant frequency. In addition, or in an alternative, as Fig. 15B As shown, a plurality of partitioned resonant units 600 may have partitions 402 located at a plurality of different z-direction positions, respectively. For example, the array of resonant units 206 may include a first partitioned resonant unit 600 having a partition 402 located at a first z-direction position, and a second partitioned resonant unit 600 having a partition 402 located at a second z-direction position. The first partitioned resonant unit 600 may be tuned to a first resonant frequency, and the second partitioned resonant unit 600 may be tuned to a second resonant frequency. For example, the resonant frequency of the first partitioned resonant unit 600 and / or the resonant frequency of the second partitioned resonant unit 600 may be tuned at least in part by selecting the z-direction position of the corresponding partition 402. In addition, or in the alternative, the resonant frequency may be tuned at least in part by selectively configuring the size of the corresponding resonant unit 206, the partition 402, and / or the aperture 404 (including by selecting a desired aperture reduction factor β). A plurality of partitioned resonant units 600 may be tuned to a desired resonant frequency. Additionally, or in the alternative, the array of resonant elements 206 may include multiple groups of partitioned resonant elements 600 that are individually tuned to desired resonant frequencies.

[0121] In some embodiments, Fig. 15C and 15D As shown, the array of resonant units 206 may include a plurality of partitioned resonant units 600 having an interface angle θ I The partitions 402 intersect the corresponding resonant spaces 208. The partitions 402 may be aligned with each other so that the partitions 402 extend through a plurality of partitioned resonant units 600 adjacent to each other. The partitions 402 may follow a linear or curved trajectory across the plurality of partitioned resonant units 600. The interface angle θ I can be selected for suitable buildability of the overhanging feature using additive manufacturing techniques. In some embodiments, by orienting the partition member 402 at a suitable interface angle θ I , partition member 402 may be provided without support member 610, thereby reducing weight and / or reducing build time. In comparison, Fig.15A and 15B Partition member 402 is shown including support member 610 , providing a generally horizontal surface oriented relative to top surface 216 . Fig. 15C and 15DThe partition member 402 is shown without the support member 610, providing the inclined partition member 402 oriented obliquely relative to the top surface 216 and the bottom surface 218. For example, when the partition member 402 has a substantially uniform cross-sectional thickness between the region proximal to one or more cell walls 300 and the region distal to one or more cell walls, the partition member 402 that does not include the support member 610 can be identified. For example, the substantially uniform cross-sectional thickness can include the same dimensions, or dimensions that differ from each other by 10% or less (e.g., 5% or less, or, for example, 1% or less).

[0122] Reference now Fig.16A and 16B as well as Figures 17A to 17D , an exemplary acoustic liner 100 and acoustic core 200 will be further described. Fig.16A and 16B As shown, the acoustic liner 100 may have a curved profile. In addition, or in the alternative, the acoustic core 200 may have a curved profile. The curved profile of the acoustic liner 100 and / or the acoustic core 200 may be configured to at least partially surround a noise source, such as a fan blade 110 of a turbine 102. For example, the acoustic liner 100 and / or the acoustic core 200 having a curved profile may conform to at least a portion of a shell or nacelle 104, such as a fan case portion 122 and / or a rotor cover portion 124 of the nacelle 104. The acoustic core 200 and / or the acoustic liner 100 may be formed to have a curved profile using a tool that provides a desired curvature. In addition, or in the alternative, the acoustic core 200 and / or the acoustic liner 100 may be formed with a first profile and then subsequently pressed or formed to present a second profile. For example, the first profile may be planar and the second profile may be curved, or the first profile may have a first curved profile and the second profile may have a second curved profile.

[0123] The acoustic core 200 having a curved profile may include vertical resonant units and / or inclined resonant units. In some embodiments, Fig.16A The resonant unit 206 in the illustrated acoustic core may include a vertical resonant unit 206, for example, having a resonant space 208 having a longitudinal axis A oriented vertically at least relative to the illustrated cross section. Fig. 16B The resonance unit 206 in the acoustic core shown may include a tilted resonance unit 206. Fig. 16B As shown, the resonant unit 206 has a resonant space 208, and the longitudinal axis of the resonant space 208 has an inclined orientation relative to the cross section shown. In addition, or in an alternative embodiment, Fig.16A The resonant unit 206 in the acoustic core shown may include an inclined resonant unit 206. For example, Fig.16AThe resonant unit 206 shown may have a resonant space 208, and the longitudinal axis A of the resonant space 208 has an inclined orientation transverse to the cross section shown. In some embodiments, at least some of the inclined resonant units 206 may have a longitudinal axis with an inclined orientation at least partially aligned with the direction of fluid flow. For example, at least some of the resonant units 206 may be inclined in the direction of fluid flow and / or at least some of the resonant units 206 may be inclined relative to the direction of fluid flow. In addition, or in an alternative, at least some of the inclined resonant units 206 may have a longitudinal axis with an inclined orientation at least partially transverse to the direction of fluid flow. For example, at least some of the resonant units may be inclined in a direction transverse to the direction of fluid flow (e.g., crosswise relative to the direction of fluid flow).

[0124] Fig.17A and 17C shows that it can be included in Fig.16A An exemplary resonant unit group 1200 in an acoustic core 200 is shown. Fig. 17B and 17D shows that it can be included in Fig. 16B The exemplary resonant unit group 1200 in the acoustic core 200 shown in FIG. Fig.17A , 17B The acoustic core 200 of the exemplary resonant unit group 1200 of the configuration shown in 17C and / or 17D can be disposed in an acoustic liner 100 that is constructed and arranged to allow fluid to flow through the top surface 216 in any desired direction. For example, Figures 17A-17D As shown, the fluid can flow through the top surface 216 from left to right, from right to left, into the page, out of the page, etc. In some embodiments, as Figures 17A-17D As shown, the acoustic core 200 may include an array of resonance units 206, which includes a plurality of resonance unit groups 1200. A corresponding resonance unit group in the plurality of resonance unit groups may include one or more convergent resonance units 1306 and / or one or more divergent resonance units 1308. The resonance unit group 1200 may include at least one convergent resonance unit 1306 and / or at least one divergent resonance unit 1308. The resonance unit group 1200 may include one or more inclined resonance units 1300 configured as convergent resonance units 1306, and / or one or more inclined resonance units 1300 configured as divergent resonance units 1308.

[0125] In some embodiments, the resonant unit group 1200 including the resonant space defined by the partition 402 may be at least partially configured as a convergent resonant unit 1306 and / or at least partially configured as a divergent resonant unit 1308. The upper resonant space 602 may be at least partially defined by the convergent resonant unit 1306, and / or the lower resonant space 604 may be at least partially defined by the divergent resonant unit 1308. In some embodiments, the resonant unit 206 not including the partition that divides the resonant space into the upper resonant space 602 and the lower resonant space 604 may be configured as the convergent resonant unit 1306 or the divergent resonant unit 1308.

[0126] In some embodiments, for example Fig.16A and 16B As shown, for example, where the acoustic core 200 is configured to conform to a radially inwardly curved surface (e.g., the radially inward side of the nacelle), the acoustic core 200 may include a diverging resonant unit 1308 defined by a top surface 216 and a bottom surface 218 at a location where the acoustic core 200 has a convex curved profile. Additionally, or in an alternative embodiment, for example Fig. 16C As shown, for example, in the case where the acoustic core is configured to adapt to a radially outward curved surface (e.g., a radially outward side of a shell or a nacelle), the acoustic core 200 may include a converging resonance unit 1306 defined by a top surface 216 and a bottom surface 218 at a location where the acoustic core 200 has a concave curve profile. In some embodiments, at least a portion of the acoustic core 200 may have a concave curve profile, and at least a portion of the acoustic core may have a convex curve profile. In addition, or in the alternative, the resonance unit 206 including the partition member 402 may be at least partially configured as a converging resonance unit 1306 and / or at least partially configured as a diverging resonance unit 1308. In some embodiments, the upper resonance space 602 may be at least partially defined by the converging resonance unit 1306, and the lower resonance space 604 may be at least partially defined by the diverging resonance unit 1308.

[0127] like Figures 17A-17D As shown, at least one converging resonance unit 1306 in the resonance unit group 1200 can be at least partially defined by the top surface 216. In addition, or in the alternative, at least one converging resonance unit 1306 can be at least partially defined by the partition 402. The first surface 606 of the partition 402 can be oriented toward the converging resonance unit 1306. The partition 402 can cross at least a portion of the resonance space 208 of the resonance unit 206. The at least one converging resonance unit 1306 can define an upper resonance space 602, and the partition 402 can demarcate the upper resonance space 602 from the lower resonance space 604. In some embodiments, the at least one converging resonance unit 1306 can be a high frequency resonance unit 1302 that defines a high frequency resonance space 1304.

[0128] At least one diverging resonant unit 1308 may be at least partially defined by the bottom surface 218. Additionally, or in the alternative, at least one diverging resonant unit 1308 may be at least partially defined by the top surface 216 and / or the partition 402. For example, the diverging resonant unit may be at least partially defined by the top surface 216 and the bottom surface 218. Additionally, or in the alternative, the diverging resonant unit may be at least partially defined by the partition 402 and the bottom surface 218. The second surface 608 of the partition 402 may be oriented toward the diverging resonant unit 1308. The partition 402 may cross at least a portion of the resonant space 208 of the resonant unit 206. At least one diverging resonant unit 1308 may define a lower resonant space 604, and the partition 402 may demarcate the lower resonant space 604 from the upper resonant space 602. In some embodiments, the partition 402 may separate the converging resonant unit 1306 from the diverging resonant unit 1308.

[0129] In some embodiments, the resonant unit group 1200 may include a coupled resonant unit 1202 that is at least partially configured as a divergent resonant unit 1308. The divergent coupled resonant unit 1202 may be configured as a tilted resonant unit 1300. The coupled resonant unit 1202 may include a divergent previous resonant space 1204 and / or a divergent subsequent resonant space 1206. In addition, or in the alternative, at least a portion of the coupled resonant space 1208 (including the previous resonant space 1204 and the subsequent resonant space 1206) may have a divergent structure. For example, the entire coupled resonant space 1208 of the coupled resonant unit 1202 may have a divergent structure. The coupled resonant space 1208 may have a relatively low resonant frequency. As Figures 17A-17D As shown, the coupled resonance unit 1202 can be grouped or matched with at least one high frequency resonance unit 1302. At least one high frequency resonance unit 1302 can be configured as a convergent resonance unit 1306. In addition, or in an alternative, as Fig. 17C and 17D As shown, the coupling resonance unit 1202 can be grouped or matched with at least one intermediate frequency resonance unit 1210 defining an intermediate resonance space 1212. At least one intermediate frequency resonance unit 1210 can be grouped or matched with at least one high frequency resonance unit 1302. At least one intermediate frequency resonance unit 1210 can be configured as a convergent resonance unit 1306. At least one intermediate frequency resonance unit 1210 can be at least partially defined by a partition member 402. The first surface 606 of the partition member 402 can be oriented toward the intermediate frequency resonance unit 1210.

[0130] like Figures 17A-17DAs shown, the converging resonant element 1306 has a cross-sectional dimension that is different between one or more locations along the longitudinal axis A of the resonant element 206. The cross-sectional dimension (c f ) may extend beyond the distal end of the top surface 216 (e.g., the proximal end of the partition member 402 (c p ) and / or the proximal end of the bottom surface 218 (c b )) of the converging resonant unit 1306. The cross-sectional dimension of the converging resonant unit 1306 can decrease along the longitudinal axis A of the resonant unit in a direction away from the top surface 216 and oriented toward the partition 402 and / or toward the bottom surface 218. The diverging resonant unit 1308 has a cross-sectional dimension that is different between one or more positions along the longitudinal axis A of the resonant unit 206. The cross-sectional dimension (c) of the diverging resonant unit 1308 at a position proximal to the bottom surface 218 is b ) may extend beyond the distal end of the bottom surface 218 (e.g., the proximal end of the partition member 402 (c p ) and / or the proximal end of the top surface 216 (c f )) of the converging resonant unit 1306. The cross-sectional dimension of the diverging resonant unit 1308 may increase along the longitudinal axis A of the resonant unit in a direction away from the top surface 216 and oriented toward the bottom surface 218, and / or in a direction away from the partition 402 and oriented toward the bottom surface 218.

[0131] As also shown, the converging resonant element 1306 can have at least one cell wall 300 that presents a convergence angle θ relative to the longitudinal axis A of the resonant element 206. The diverging resonant element 1308 can have at least one cell wall 300 that presents a divergence angle θ relative to the longitudinal axis A of the resonant element 206. Convergence angles can sometimes be used to describe the diverging resonant element 1308 and / or its cell walls 300; for example, the diverging resonant element 1308 can have at least one cell wall that presents a negative convergence angle θ relative to the longitudinal axis A of the resonant element 206. Divergence angles can sometimes be used to describe the converging resonant element 1306 and / or its cell walls 300; for example, the converging resonant element 1306 can have at least one cell wall that presents a negative divergence angle θ relative to the longitudinal axis A of the resonant element 206.

[0132] In some embodiments, for example Fig.17AAs shown, the converging resonance unit 1306 can have one or more geometric symmetry characteristics. For example, the cell walls 300 of the converging resonance units 1306 facing each other can have a common convergence angle θ. In addition, or in the alternative, the cell walls 300 of the converging resonance units 1306 facing each other can have a common cross-sectional dimension determined from the longitudinal axis A to the corresponding cell wall 300. In addition, or in the alternative, the diverging resonance unit 1308 can have one or more geometric symmetry characteristics. For example, the cell walls 300 of the diverging resonance units 1308 facing each other can have a common divergence angle θ. In addition, or in the alternative, the cell walls 300 of the diverging resonance units 1308 facing each other can have a common cross-sectional dimension determined from the longitudinal axis A to the corresponding cell wall 300.

[0133] In some embodiments, for example Fig. 17B As shown, the converging resonance unit 1306 can have one or more geometrically asymmetric characteristics. For example, the cell walls 300 of the converging resonance units 1306 facing each other can differ from each other in terms of their respective convergence angles θ. In addition, or in the alternative, the cell walls 300 of the converging resonance units 1306 facing each other can differ from each other in terms of the cross-sectional dimensions determined from the longitudinal axis A to the corresponding cell walls 300. In addition, or in the alternative, the diverging resonance unit 1308 can have one or more geometrically asymmetric characteristics. For example, the cell walls 300 of the diverging resonance units 1308 facing each other can differ from each other in terms of their respective divergence angles θ. In addition, or in the alternative, the cell walls 300 of the diverging resonance units 1308 facing each other can differ from each other in terms of the cross-sectional dimensions determined from the longitudinal axis A to the corresponding cell walls 300.

[0134] The cross-sectional dimensions and / or convergence angles of the resonant cells 206 (e.g., the converging resonant cells 1306 and / or the diverging resonant cells 1308) may be achieved by the angle or orientation of one or more cell walls 300, and / or by the thickness of one or more cell walls 300. For example, the converging resonant cell 1306 may include one or more cell walls having a position (c 214) proximal to the top surface 216. f ) to the position near the partition (c p ) or the position near the bottom surface 218 (c b ) increased thickness. In addition, or in the alternative, the divergent resonant unit 1308 may include one or more unit walls having a position (c b ) to the position near the partition (c p ) or the position near the top surface 216 (c f )Increased thickness.

[0135] The divergence angle θ and / or the convergence angle θ are determined with reference to the longitudinal axis A of the resonant unit 206 and / or with reference to a plane (e.g., the top surface 216, the bottom surface 218, and / or the partition 402) that intersects the resonant unit 206. As determined with reference to the longitudinal axis A of the resonant unit 206, the divergence angle θ and / or the convergence angle θ can be from about 0.5 degrees to about 30 degrees, such as from about 0.5 degrees to about 15 degrees, such as from about 0.5 degrees to about 5 degrees, such as from about 2 degrees to about 5 degrees, such as from about 0.5 degrees to about 10 degrees, such as from about 0.5 degrees to about 5 degrees, such as from about 0.5 degrees to about 3 degrees, or such as from about 10 degrees to about 30 degrees. As determined with reference to a plane transverse to the resonant unit 206, the divergence angle θ and / or the convergence angle θ can be from about 60 degrees to about 89.5 degrees, for example from about 75 degrees to about 89.5 degrees, for example from about 85 degrees to about 89.5 degrees, for example from about 85 degrees to about 89.5 degrees, for example from about 85 degrees to about 89.5 degrees, for example from about 80 degrees to about 89.5 degrees, for example from about 85 degrees to about 89.5 degrees, for example from about 87 degrees to about 89.5 degrees, or for example from about 60 degrees to about 80 degrees.

[0136] like Fig.17A and 17D As shown, in some embodiments, the orientation (e.g., slope) of the cell wall 300 can be different relative to different positions along the longitudinal axis A of the resonant cell 206. For example, a first portion of the cell wall 300 can define at least a portion of the converging resonant cell 1306, and a second portion of the cell wall can define at least a portion of the diverging resonant cell 1308. The first portion of the cell wall 300 can have a first orientation (e.g., a first slope) that is different from a second orientation (e.g., a second slope) of the second portion of the cell wall 300. In some embodiments, the angle between the first portion of the cell wall 300 that defines a portion of the converging resonant cell 1306 and the second portion of the cell wall 300 that defines a portion of the diverging resonant cell 1308 can be less than about 180 degrees, such as from about 170 degrees to about 179 degrees, or from about 175 degrees to about 179 degrees.

[0137] Reference now Fig.18, another exemplary resonant unit group 1200 will be described. As shown, the resonant unit group 1200 may include a coupled resonant unit 1202, which includes at least one previous resonant space 1204 and a plurality of subsequent resonant spaces 1206, or a plurality of previous resonant spaces 1204 and at least one subsequent resonant space 1206. The coupled resonant unit 1202 may define a coupled resonant space 1208, wherein the previous resonant space 1204 is in fluid communication with a first subsequent resonant space 1206 and a second subsequent resonant space 1206. The first subsequent resonant space 1206 may be at least partially defined by the partition member 402. The second subsequent resonant space 1206 may be at least partially defined by the top surface 216. The second subsequent resonant space 1206 may also serve as the previous resonant space 1204. For example, an acoustic wave may propagate from the top surface 216 into the first portion 1800 and / or the second portion 1802 of the coupled resonant unit 1202. Regarding the sound waves propagating from the top surface 216 into the first portion 1800 of the coupling resonance unit 1202, the first portion 1800 of the coupling resonance unit 1202 may be the previous resonance space 1204, and the second portion 1802 of the coupling resonance unit 1202 may be the subsequent resonance space 1206. The sound waves propagating from the top surface 216 into the first portion 1800 of the coupling resonance unit 1202 may be preferentially attenuated relative to relatively low frequencies. Regarding the sound waves propagating from the top surface 216 into the second portion 1802 of the coupling resonance unit 1202, the second portion 1802 of the coupling resonance unit 1202 may be the subsequent resonance space 1206, and the first portion 1800 of the coupling resonance unit 1202 may be the previous resonance space 1204. The sound waves propagating from the top surface 216 into the second portion 1802 of the coupling resonance unit 1202 may be preferentially attenuated relative to intermediate frequencies. The coupling resonance unit 1202 may be grouped or matched with the high-frequency resonance unit 1302 that preferentially attenuates sound waves relative to relatively high frequencies. The high frequency resonance unit 1302 may be configured as a convergent resonance unit 1306. The partition member 402 may at least partially separate the high frequency resonance unit 1302 from the coupling resonance unit 1202, for example, from a subsequent resonance space 1206 of the coupling resonance unit 1202. For example, the high frequency resonance unit 1302 may define an upper resonance space 602, and the subsequent resonance space 1206 of the coupling resonance unit 1202 may define a lower resonance space 604.

[0138] The cell walls 300 and / or partitions 402 of the array of resonant cells 206 may have any desired thickness, which may be selected, for example, based at least in part on desired strength and / or ductility properties, and / or based at least in part on balanced strength and / or ductility properties with the corresponding weight of the array of resonant cells 206. The cell walls 300 and partitions 402 may have uniform or varying thicknesses in various regions and / or relative to each other. The thickness of the cell walls 300 may be determined at the midpoint of the resonant space 208 defined by the cell walls 300. The thickness of the partitions 402 may be determined at the midpoint of the partitions 402 between opposing cell walls, or, for a partition 402 having one or more partition apertures 616, may be determined at the midpoint between the partition apertures 616 and the cell wall 300, or at the midpoint between the partition apertures 616, respectively. When the cell walls 300 or partitions 402 have variable thicknesses, an average, maximum, and / or minimum thickness may be determined. In some embodiments, the cell wall 300 and / or the partition member 402 may have a thickness of from 0.002 inches to 0.5 inches (e.g., from 0.01 inches to 0.5 inches, e.g., from 0.01 inches to 0.25 inches, e.g., from 0.01 inches to 0.1 inches, e.g., from 0.02 inches to 0.08 inches, e.g., from 0.02 to 0.14 inches). The cell wall 300 and / or the partition member 402 may have a thickness of less than 0.5 inches (e.g., less than 0.5 inches, e.g., less than 0.25 inches, e.g., less than 0.1 inches, e.g., less than 0.08 inches, e.g., less than 0.05 inches, e.g., less than 0.04 inches, e.g., less than 0.03 inches, e.g., less than 0.02 inches). The cell walls 300 and / or partitions 402 can have a thickness of at least 0.002 inches (e.g., at least 0.01 inches, such as at least 0.02 inches, such as at least 0.03 inches, such as at least 0.04 inches, such as at least 0.05 inches, such as at least 0.08 inches, such as at least 0.1 inches, such as at least 0.25 inches). Such thickness values ​​can be determined with reference to a point (e.g., a midpoint), an average, a maximum, and / or a minimum. Other thicknesses are also contemplated and can vary depending on the desired embodiment of the resonant cell 206 and / or the acoustic liner 100. For example, the cell walls 300 and / or partitions 402 can be constructed to have a thickness selected at least in part based on providing a desired design intent, such as a thickness selected to provide a certain mechanical stiffness and / or resilience while minimizing weight. For example, in some embodiments, the cell walls may include areas of varying thickness and / or mechanical reinforcements (e.g., areas of increased thickness relative to the nominal cell wall thickness) that act as beams through the wall to provide desired stiffness and / or resilience (e.g., with respect to vibration resistance, structural loads, etc.).

[0139] In addition to the exemplary resonant unit 206 described above, the acoustic core 200 may include resonant units having many other configurations. For example, Fig.19 A number of exemplary polyhedrons are shown from which configurations for resonant units and / or arrays of resonant units may be selected. Exemplary resonant units and / or arrays of resonant units may include Fig.19 . As an example, the exemplary resonant unit 206 may include a frustum, a rhombus, a cylinder or a cone (for example, a cylinder or a cone may be described as an n-angle prism, where n is increasing, for example, n approaches 100, 1,000, 10,000 or infinity), an inverse prism, a distorted prism, a toroid, a dome (including a star-shaped dome), a wedge, a pyramid, and combinations or portions of these. The frustum may include a triangular frustum, a quadrilateral frustum, a pentagonal frustum, a hexagonal frustum, a heptagonal frustum, an octagonal frustum, a nonagonal frustum, a decagonal frustum, an eleven-sided frustum, a dodecagonal frustum, any other truncated polyhedron, and combinations of these. A truncated polyhedron includes a frustum combined with another polyhedron, including any of the above frustum shapes combined with another polyhedron. For example, a rhombohedron may be formed from any rhombus, providing a rhombic polyhedron. As a further example, a rhombohedron may be combined with a frustum to form a rhombic frustum.

[0140] The anti-prism includes a polyhedron composed of a polygonal top surface 216, a polygonal bottom surface 218, and a series of adjacent triangular unit walls 300 with alternating orientations, which is divided into two by the top surface 216 and the bottom surface 218. The anti-prism may include a triangular anti-prism, a quadrilateral anti-prism, a hexagonal anti-prism, an anti-prismatic polyhedron, and a combination of these. The anti-prism polyhedron includes an anti-prism combined with another polyhedron. In some embodiments, the anti-prism may include an n-side top surface 216 and an n-side bottom surface 218. Alternatively, the anti-prism may include an n-side top surface 216 and a bottom surface 218 that is larger or smaller than the n-side.

[0141] The distorted prism includes a polyhedron consisting of a polygonal top surface 216, a polygonal bottom surface 218, and a plurality of cell walls 300, wherein the plurality of cell walls 300 include at least some cell walls 300 that are bisected on a diagonal line, wherein the top surface 216 and the bottom surface 218 are distorted relative to each other, resulting in at least some adjacent cell walls 300 being concave relative to each other. The distorted prism may include Polyhedron, tetrahedral distorted prism, hexagonal distorted prism, distorted prismatic polyhedron and combinations thereof. The distorted prism has one or more cell walls 300 that are bisected on adjacent diagonals or on subsequent diagonals.

[0142] The toroid may include a polyhedron consisting of a polygonal or non-polygonal top surface 216, a polygonal or non-polygonal bottom surface 218, and one or more cell walls. The toroid may include a quadrilateral toroid or a cylindrical toroid (e.g., an n-sided toroid, where n is getting larger, such as where n approaches 100, 1,000, 10,000, or infinity).

[0143] The dome body includes a polyhedron composed of a polygonal top surface 216, a polygonal bottom surface 218 and a plurality of cell walls 300, wherein the plurality of cell walls 300 include triangular cell walls 300 and quadrilateral cell walls in an alternating sequence. In some embodiments, the dome body has a top surface 216, and the edge of the top surface 216 is twice the edge of its bottom surface 218, or vice versa. The dome body includes a triangular dome body having a quadrilateral top surface 216 and a hexagonal bottom surface 218, or a hexagonal top surface 216 and a quadrilateral bottom surface 218; and a pentagonal dome body having a pentagonal top surface 216 and a decagonal bottom surface 218, or vice versa. The dome body also includes a star-shaped dome body, which is a dome body in which the quadrilateral cell wall 300 is replaced by an adjacent concave triangular cell wall. The star-shaped dome body includes a pentagonal cup-shaped body and a heptagonal cup-shaped body. A pentagonal cup-shaped body has a pentagonal bottom surface 218 and a pentagonal top surface 216, or vice versa. A heptagonal cup-shaped body has a heptagonal top surface 216 and a heptagonal bottom surface 218, or vice versa. As a further example, a dome body includes a cup-shaped configuration having a plurality of cell walls, including a configuration approaching a truncated cone as the number of cell walls 300 increases. For example, a dome body includes an octagon, which has eighty cell walls. A dome body also includes a cup-shaped polyhedron, which includes a dome body or a cup-shaped body combined with another polyhedron.

[0144] The wedge includes a polyhedron having a polygonal top surface 216 and a plurality of polygonal cell walls 300 converging into a line. The wedge may include a tetrahedral wedge, a blunt wedge, an acute wedge, and a wedge-shaped polyhedron, and combinations thereof. A tetrahedral wedge has two triangular cell walls 300 and two quadrilateral cell walls. The cell wall 300 is bisected by a quadrilateral plane on one side and converges into a line on the other side. A blunt wedge converges into a line wider than the opposite quadrilateral plane. An acute wedge converges into a line narrower than the opposite quadrilateral plane. A wedge-shaped polyhedron includes a wedge combined with another polyhedron.

[0145] The pyramid includes a polyhedron having a polygonal base, which is divided into two by a plurality of triangular unit walls 300 that converge into a point. The pyramid includes a quadrilateral pyramid composed of quadrilateral faces, which is divided into two by four triangular unit walls 300 that converge into a point. The pyramid also includes a star-shaped pyramid, which is composed of a star-shaped polygonal base and a plurality of triangular unit walls 300 that converge into a point. For example, the star-shaped pyramid includes a pentagonal star-shaped pyramid.

[0146] In some embodiments, the acoustic core 200 may be an injection molded acoustic core 200 formed by a molding process, such as an injection molding process and / or a compression molding process. One or more structural features of the acoustic core 200 may be configured to facilitate the use of an injection molding process to form an injection molded acoustic core 200 including various other structural features according to the present disclosure. In addition, or in the alternative, one or more structural features of the acoustic core 200 may be configured to facilitate the use of a press forming process (e.g., rolling or stamping) to form a pressed rolled acoustic core 200 including various other structural features according to the present disclosure. For example, the acoustic core may at least partially include a converging resonant unit and / or a diverging resonant unit to allow the geometry of the resonant unit to inherently provide a draft angle (draft angle) sufficient to release the acoustic core well during the injection molding or forming process (if applicable), while providing the desired noise attenuation characteristics in the desired frequency range. In addition, or in the alternative, the acoustic core may include a converging resonant unit and / or a diverging resonant unit, which allows the partition to be formed integrally with the unit wall using an injection molding process or a compression forming process.

[0147] It should be understood that the examples of the above-mentioned structural features are provided only as examples and are not limiting. In fact, it should be understood that the resonant unit also includes other currently disclosed structural features, at least in part by means of the resonant unit, and the resonant unit also having other currently disclosed structural features can be included in the injection molded acoustic core and / or the press-formed acoustic core. In addition, or in the alternative, the tool assembly and / or the forming tool can be configured to provide an injection molded and / or press-formed acoustic core having various currently disclosed structural features, at least in part by the construction of such tool assembly and / or forming tool.

[0148] It should also be understood that other manufacturing techniques may be used in addition to or in lieu of the injection molding and / or press forming discussed herein to achieve an acoustic core having the presently disclosed structural features, such as additive manufacturing and / or various other manufacturing techniques disclosed herein. However, the selection of a production technique for producing an acoustic core and / or an acoustic liner may be at least partially influenced by considerations such as production capacity and / or production costs, and therefore, the presently disclosed structural features that facilitate the use of certain production techniques to form an acoustic core having certain other presently disclosed structural features may be of particular interest to those who may wish to utilize the teachings of the present disclosure.

[0149] Reference now Figures 20A-20I, an exemplary tool assembly 2000 will be described. The exemplary tool assembly 2000 may include one or more forming tools 2002. According to some embodiments of the present disclosure, the exemplary tool assembly 2000 and / or the forming tool 2002 may be used to form the acoustic core 200. The exemplary tool assembly 2000 and / or the one or more forming tools 2002 may be used to form the acoustic core 200, for example, using a molding process (such as injection molding or compression molding). The tool assembly 2000 may be configured as or used for a molding component, such as an injection molding component or a compression molding component. One or more forming tools 2002 may be configured as or used for a molding tool, such as an injection molding tool or a compression molding tool, respectively. In addition, or in the alternative, the exemplary tool assembly 2000 and / or the one or more forming tools 2002 may be used to form the acoustic core 200 using a forming process (such as rolling or stamping). The tool assembly 2000 may be configured as or used for a press-formed component, such as a rolling component or a stamping component. One or more forming tools 2002 may be configured or used as forming tools, such as rolling tools or stamping tools. The exemplary tool assembly 2000 may include a forming tool 2002 made of a relatively hard material, such as aluminum, nickel, steel alloys, etc. Additionally, or in the alternative, the exemplary tool assembly 2000 may include a forming tool 2002 made of a relatively soft material, such as silicone, carbon fiber, or glass fiber.

[0150] As an example, Fig. 20A An exemplary tool assembly 2000 is shown, and Fig. 20B and 20C shows that it can be included in Fig. 20A2002 in the tool assembly 2000 shown in . As shown, the exemplary forming tool 2002 may include one or more support members 2004 and a plurality of forming elements 2006. The plurality of forming elements 2006 may be coupled to the support member 2004. In addition, or in the alternative, the plurality of forming elements 2006 may be integrally formed as part of the support member 2004. The support member 2004 may be configured as and / or may include a clamp, a pressure plate, etc. During operation of the tool assembly 2000, one or more forming tools 2002 may be movable or stationary. For example, the exemplary tool assembly 2000 may include a movable forming tool 2002 and a stationary forming tool 2002. The movable forming tool 2002 may be close to the stationary forming tool 2002 to form the acoustic core 200. For example, in the case of the injection molding tool assembly 2000, the stationary forming tool 2002 may sometimes be referred to as a cavity element, and / or the movable forming tool 2002 may sometimes be referred to as a core element. The tool assembly 2000 may include a plurality of guide pins (not shown) configured to align corresponding forming tools in the plurality of forming tools 2002 with each other. In some embodiments, the tool assembly 2000 may include a top forming tool 2001 and a bottom forming tool 2003. The top forming tool 2001 may correspond to the top surface 216 of the acoustic core, and the bottom forming tool may correspond to the bottom surface 218 of the acoustic core. The top forming tool 2001 may be configured as a cavity element and / or a core element. In addition, or in an alternative, the top forming tool 2001 may be configured as a stationary forming tool 2002 and / or a movable forming tool 2002. The bottom forming tool 2003 may be configured as a cavity element and / or a core element. In addition, or in an alternative, the bottom forming tool 2003 may be configured as a stationary forming tool 2002 and / or a movable forming tool 2002. For example, the top forming tool 2001 may be configured as a stationary forming tool 2002, and the bottom forming tool 2003 may be configured as a movable forming tool 2002. Additionally, or in the alternative, the top forming tool 2001 may be configured as a moving forming tool 2002 and the bottom forming tool 2003 may be configured as a stationary forming tool 2002 .

[0151] When a plurality of forming tools 2002 are close to each other, the space between the forming elements 2006 can define a mold cavity 2008. The forming tool 2002 can include one or more gate elements 2010, through which a moldable material can be injected into the mold cavity 2008. Exemplary moldable materials can include polymer materials, such as thermoplastic materials and / or thermosetting materials, such as those described herein. In the case of an injection molding process, the moldable material can be heated to a softened or fluid state to allow the moldable material to be injected into the mold cavity 2008. The moldable material can be actively or passively cooled. After the moldable material has cooled, the forming tools defining the mold cavity 2008 can be separated from each other, and the acoustic core 200 formed by the tool assembly 2000 can be removed. In some embodiments, for example in the case of injection molding or compression molding, one or more forming tools 2002 may include one or more ejector pins 2012 that may extend through the support member 2004 and / or through the corresponding forming element 2006 to push the acoustic core 200 away from the corresponding forming tool 2002 and out of the mold cavity 2008.

[0152] As shown, tool assembly 2000 and / or forming tool 2002 can be configured to form an acoustic core 200, such as an acoustic core having a curved profile. As an example, in the case where acoustic core 200 is configured to fit a radially inward curved surface (such as a radially inward side of a nacelle), Figures 20A-20I The tool assembly 2000 and forming tool 2002 shown can be configured to form an acoustic core 200 having a convex curved profile. In addition, or in the alternative, the tool assembly 2000 and / or the forming tool 2002 can be configured to form an acoustic core 200 having a concave curved profile, and / or an acoustic core 200 including at least one concave portion and at least one convex portion having a corresponding curved profile. It should be understood that the curved profiles shown are provided as examples and are not limiting. In fact, according to the present disclosure, one or more tool assemblies 2000 and / or corresponding forming tools 2002 can be used to form an acoustic core 200 having any desired curved profile. Similarly, the tool assembly 2000 and / or the corresponding forming tool 2002 can be provided with any desired curved profile.

[0153] In some embodiments, the forming tool 2002 may include a die having a draft angle θ d The one or more forming elements 2006 are formed such that the cross-sectional dimensions of the forming elements decrease from a location proximal to the support element 2004 to a location distal to the support element 2004 by an amount suitable to allow good release of the acoustic core 200 from the forming tool 2002. The draft angle may be determined with reference to the longitudinal axis A of the corresponding forming element 2006 and / or a plane equidistant from the longitudinal axis of the forming element 2006. The draft angle θ dThe cross-sectional dimension c of the proximal end of the support element 2004 may correspond to the difference in the cross-sectional dimension between the position of the shaping element 2006 at the proximal end of the support element 2004 and the position of the distal end of the support element 2004, so that the cross-sectional dimension c of the proximal end of the support element 2004 is i The cross-sectional dimension c beyond the distal end of the support element ii .

[0154] Draft angle θ sufficient to provide good release d The size of the resonant unit 206 of the acoustic core 200 (e.g., one or more dimensions of the one or more cell walls 300 and / or the size of the one or more resonant spaces 208 defined by the one or more cell walls) may be provided. For example, the size of the resonant unit 206 may have a convergence angle θ that inherently corresponds to a suitable draft angle θ. d Additionally, or in the alternative, one or more dimensions of the shaping element 2006 may be different from corresponding dimensions of the cell wall 300 and / or the resonant space 208 in order to provide a desired draft angle θ d For example, the convergence angle θ of one or more resonant units 206 may be introduced and / or enhanced to provide a suitable draft angle θ d Additionally, or in the alternative, the forming tool 2002 may be configured with a draft angle θ that is different from the corresponding convergence angle θ. d .

[0155] The draft angle θ is sufficient to allow the acoustic core 200 to be reliably and well released from the forming tool 2002. d The draft angle θ may depend at least in part on the length of the corresponding forming element 2006. Generally, a relatively long forming element 2006 may require a relatively large draft angle. In some embodiments, the draft angle θ suitable for good release of the acoustic core from the forming tool 2002 is d It may be from about 0.5 degrees to about 10 degrees, such as from about 0.5 degrees to about 5 degrees, or such as from about 0.5 degrees to about 3 degrees.

[0156] The mold cavity 2008 defined by one or more forming tools 2002 of the tool assembly 2000 may correspond to at least a portion of the acoustic core 200. As an example, Fig. 20A The tool assembly 2000 shown in FIG. Figures 20A-20C The forming tool 2002 shown in FIG. 2 may correspond to a forming tool including Fig.17A As another example, Figures 20D-20F The forming tool 2002 shown in FIG. Fig.20F The tool assembly 2000 shown in FIG. 2 may correspond to a tool assembly including Fig. 17CIt should be understood that the forming assembly 2000 and forming tool 2002 shown are provided as examples, not limitations, and that the forming assembly 2000 and forming tool 2002 can be configured to form the acoustic core 200 in any desired configuration, including the forming assembly 2000 and forming tool 2002 being configured to form any acoustic core 200 described in the present disclosure.

[0157] One or more forming tools 2002 may provide a mold cavity 2008 configured to form one or more resonant units 206, such as an array of resonant units 206, of the acoustic core 200. The plurality of forming elements 2006 of the forming tool 2002 may correspond to respective resonant spaces 208 of the resonant units 206. The mold cavity 2008 may be aligned with the unit walls 300 of the resonant units 206. In some embodiments, one or more gate elements 2010 may be aligned with at least some of the unit walls 300. In some embodiments, one or more ejector pins 2012 may push against the support element 2004 of the mating forming tool 2002 when actuated, and / or push against the partitioning member 402 of the resonant unit 206 formed by the tool assembly 2000.

[0158] In some embodiments, for example, Figures 20G-20I As shown, tool assembly 2000 and / or one or more forming tools 2002 may be configured to form resonant unit 206, which includes a resonant unit having, for example, a reference Figure 4A and 4B and / or Figures 6A-6E Partitioning member 402 of one or more partitioned apertures 616 described. For example, as shown, the forming element 2006 may include a protrusion 2014 extending from a body portion 2016 of the forming element 2006. The protrusion 2014 may be in proximity to and / or contact with a mating forming element 2006 of a corresponding forming tool 2002. When the acoustic core 200 is formed using the tool assembly 2000, the protrusion 2014 may define the perimeter of the partitioned aperture 616 of the resonant unit 206. The proximity and / or contact between the protrusion 2014 and the mating forming element 2006 may be sufficient to restrict moldable material from entering the space where the aperture will be formed by the protrusion 2014. In some embodiments, the forming element 2006 may include a plurality of protrusions 2014. The plurality of protrusions 2014 may be configured to form a plurality of partitioned apertures 616, for example, with reference to Figures 7A-7D and / or Fig. 8A -D and / or Figures 9A-9F as described.

[0159] Fig.21A shows at least part of the use of Fig. 20A The tool assembly 2000 shown in FIG. Fig. 20C and 20CAn exemplary acoustic core 200 formed by the forming tool shown in FIG. As an example, Fig.21D An exemplary acoustic liner 100 is shown, which includes using Figures 20G-20I The acoustic core 200 is formed by the tool assembly 2000 and the forming tool 2002 shown in FIG. In some embodiments, the acoustic liner 100 can be at least partially formed by the acoustic core 200 (e.g., Fig.21A The acoustic core 200 shown in FIG. 2 ), the acoustic screen 202 (eg, Fig. 21B ) and / or the backplane 204 (e.g. Fig. 21C The acoustic core 200 may be secured between the acoustic shield 202 and the backing plate 204 using an adhesive process and / or a heat, sonic or electrical welding process.

[0160] Now turn to Fig.22A and 22B , an exemplary method 2200 of making an acoustic core 200 and / or an acoustic liner will be described. Fig.22A As shown, the exemplary method 2200 may include determining the configuration of the acoustic core 200 including the array of resonant units 206 at box 2202. The exemplary method 2200 may include producing the acoustic core 200 including the array of resonant units at box 2204. In some embodiments, the exemplary method 2200 may include producing the acoustic liner 100 including the acoustic core 200 at box 2206. The acoustic liner 100 may include an acoustic screen 202 and / or a back plate 204. Determining the configuration of the acoustic core 200 may include determining the configuration of the acoustic screen and / or the back plate. Producing the acoustic core 200 may include producing the acoustic screen and / or the back plate. The acoustic core 200 including the array of resonant units, the acoustic screen and / or the back plate may be produced using additive manufacturing technology. Any suitable additive manufacturing technology may be used. The corresponding resonant unit in the resonant unit in the array includes one or more unit walls 300 and a resonant space defined by the one or more unit walls. The resonant element array may be arranged at an element angle θ greater than 0 degrees relative to a normal line 214 represented by the axis R. C Tilted orientation. Tilted orientation can improve the constructability and build quality of the resonant unit array.

[0161] Still reference Fig.22AIn some embodiments, the exemplary method 2200 may include determining, at block 2208, a configuration of a plurality of coupled resonant cells 1202, respective coupled resonant cells of the plurality of coupled resonant cells 1202 defining a preceding resonant space 1204 and a subsequent resonant space and having at least one cell wall 300, the at least one cell wall 300 having one or more wall apertures defining a passage between the preceding resonant space 1204 and the subsequent resonant space. The cross-sectional dimensions of the one or more wall apertures defining the passage between the preceding resonant space 1204 and the subsequent resonant space may be smaller than the cross-sectional dimensions of the preceding resonant space 1204 and / or the cross-sectional dimensions of the subsequent resonant space. The cross-sectional dimensions of the preceding resonant space 1204 and / or the cross-sectional dimensions of the subsequent resonant space may be determined adjacent to the one or more wall apertures.

[0162] In some embodiments, block 2208 of exemplary method 2200 may include determining a resonant frequency of a low frequency sound wave that is desired to be attenuated, and tuning the plurality of coupled resonant cells 1202 to the resonant frequency of the low frequency sound wave that is desired to be attenuated, wherein a resonant length of a corresponding coupled resonant cell in the plurality of coupled resonant cells 1202 exceeds a height or an axial length of the corresponding resonant cell 1202 and / or a height of acoustic core 200. The resonant length of a corresponding coupled resonant cell in the plurality of coupled resonant cells 1202 may exceed the height or axial length of acoustic core 200 at least in part by having a cross-sectional dimension of one or more wall apertures defining a passage between a previous resonant space 1204 and a subsequent resonant space that is smaller than a cross-sectional dimension of the previous resonant space 1204 and / or a cross-sectional dimension of the subsequent resonant space.

[0163] The exemplary method 2200 may additionally or alternatively include determining, at block 2210, a configuration of a plurality of high-frequency resonance units 1302 that respectively define a high-frequency resonance space 1304. A corresponding high-frequency resonance unit in the plurality of high-frequency resonance units 1302 may be matched with a corresponding coupling resonance unit in the plurality of coupling resonance units 1202. In the exemplary method, block 2210 may additionally or alternatively include determining a resonance frequency of a high-frequency sound wave that is desired to be attenuated, and tuning the plurality of high-frequency resonance units 1302 to the resonance frequency of the high-frequency sound wave that is desired to be attenuated. In an exemplary embodiment, a resonance length of a corresponding high-frequency resonance unit in the plurality of high-frequency resonance units 1302 may exceed a height or an axial length of the corresponding high-frequency resonance unit 1302.

[0164] The exemplary method 2200 may additionally or alternatively include determining the configuration of a plurality of intermediate frequency resonance units 1210 that respectively define intermediate frequency resonance spaces at block 2212. A corresponding intermediate frequency resonance unit in the plurality of intermediate frequency resonance units 1210 may be matched with a corresponding coupling resonance unit in the plurality of coupling resonance units 1202 and / or a corresponding high frequency resonance unit in the plurality of high frequency resonance units 1302. In the exemplary method, block 2212 may additionally or alternatively include determining the resonance frequency of the intermediate frequency sound wave that is desired to be attenuated, and tuning the plurality of intermediate frequency resonance units 1210 to the resonance frequency of the intermediate frequency sound wave that is desired to be attenuated. The resonance length of a corresponding intermediate frequency resonance unit in the plurality of intermediate frequency resonance units 1210 may exceed the height or axial length of the corresponding intermediate frequency resonance unit 1210.

[0165] The exemplary method 2200 may additionally or alternatively include determining a configuration of a plurality of partitioned resonant units at block 2214, wherein a corresponding partitioned resonant unit of the plurality of partitioned resonant units has a partition 402 that crosses a corresponding resonant space of the partitioned resonant unit. In some embodiments, the subsequent resonant space of at least some of the plurality of coupled resonant units 1202 may define a lower resonant space 604 of at least some of the plurality of partitioned resonant units. Additionally or alternatively, the high frequency resonant space 1304 of at least some of the high frequency resonant units 1302 may define an upper resonant space of at least some of the plurality of partitioned resonant units. Additionally or alternatively, the intermediate frequency resonant space of at least some of the intermediate frequency resonant units 1210 may define an upper resonant space of at least some of the plurality of partitioned resonant units.

[0166] In the exemplary method 2200, determining the configuration of the plurality of coupled resonant cells 1202 at block 2208 may include determining a cross-sectional size of one or more wall apertures defining a passage between a previous resonant space 1204 and a subsequent resonant space based at least in part on an aperture reduction factor β. Additionally, or in the alternative, block 2208 may include determining a cross-sectional size of the previous resonant space 1204 and / or a cross-sectional size of the subsequent resonant space based at least in part on the aperture reduction factor β. The aperture reduction factor β may be determined based at least in part on a relationship between the aperture reduction factor β and a resonant frequency of the resonant cell. The relationship between the aperture reduction factor β and the resonant frequency may include decreasing the resonant frequency as the aperture reduction factor β increases. The relationship between the aperture reduction factor β and the resonant frequency may include a linear region and a nonlinear region (e.g., an asymptotic region). The determined aperture reduction factor β may correspond to the nonlinear region (e.g., an asymptotic region).

[0167] Reference now Fig. 22B, an exemplary method 2200 for making an acoustic core 200 and / or an acoustic liner will be further described. In some embodiments, an exemplary method 2200 for making an acoustic core 200 and / or an acoustic liner may include reference Fig.22A One or more of the steps described. Fig.22A The steps described may include reference to Fig. 22B In addition, or in the alternative, reference is made to Fig. 22B One or more of the steps described may be combined with reference to Fig.22A For example, the step of producing the acoustic core 200 including the array of resonant units 206 at block 2204 may include referring to Fig. 22B Additionally, or in the alternative, the step of producing the acoustic liner 100 including the acoustic core 200 at block 2206 may include referring to Fig. 22B One or more of the steps described.

[0168] like Fig. 22B As shown, the exemplary method 2200 for producing the acoustic core 200 and / or the exemplary method 2200 for producing the acoustic liner 100 may include determining, at block 2216, a configuration of the tool assembly 2000 using the acoustic core construction system 2302, and / or a configuration of one or more forming tools 2002 for use in the tool assembly 2000. The forming tool 2002 and / or the tool assembly 2000 may be configured to produce the acoustic core 200 including the array of resonant units 206. The configuration of the tool assembly 2000 and / or the configuration of one or more forming tools 2002 may be determined based at least in part on the configuration of the acoustic core 200, for example, according to block 2202 and / or reference 2302. Fig.22A The one or more forming tools 2002 and / or tool assemblies 2000 may be as described herein, for example, with reference to Figures 20A-20I In some embodiments, the one or more forming tools 2002 may include a draft angle θ sufficient to provide good release of the acoustic core 200 from the one or more forming tools 2002. d .

[0169] In some embodiments, the exemplary method 2200 may include making one or more forming tools 2002 and / or assembling a tool assembly 2000 including one or more forming tools 2002 at block 2218. The one or more forming tools 2002 may have a configuration determined based at least in part on the configuration determined for the acoustic core 200. In some embodiments, the exemplary method 2200 may include forming the acoustic core 200 using the tool assembly 2000 including the one or more forming tools 2002 at block 2220. In some embodiments, the exemplary method 2200 may include forming the acoustic shield 202 and / or forming the backing plate 204 at block 2222. Additionally, or in the alternative, in some embodiments, the exemplary method 2200 may include forming the acoustic liner 100 at least in part by attaching the acoustic shield 202 and the acoustic core 200 to each other and / or by attaching the backing plate 204 and the acoustic shield 202 to each other at block 2224.

[0170] In some embodiments, the presently disclosed methods (including reference Fig.22A and 22B The exemplary method 2200 described may be performed at least in part using a computer-implemented solution (e.g., software or hardware configured to use an acoustic core construction module) to determine the construction of an acoustic core including an array of resonant units and / or one or more resonant unit groups. In some embodiments, the exemplary method may be performed using an acoustic core manufacturing system and / or its various features. In some embodiments, an optimization algorithm may be used. The algorithm may include an attenuation model. As an example, an attenuation model may be applied to a baseline noise spectrum in order to evaluate various design parameters for a given construction of an acoustic core, and / or to evaluate various design parameters of the resonant units and / or resonant unit groups that make up the acoustic core.

[0171] Now turn to Fig.23 , an exemplary acoustic core manufacturing system 2300 and an acoustic core construction system 2302 will be described. The exemplary acoustic core manufacturing system 2300 may include the acoustic core construction system 2302. Additionally, or in the alternative, the acoustic core construction system 2302 may be provided separately from the acoustic core manufacturing system 2300. The acoustic core manufacturing system 2300 and / or the acoustic core construction system 2302 may include a computer-readable medium configured to determine the construction of the acoustic core 200. Additionally, or in the alternative, the computer-readable medium may be configured to operate the acoustic core manufacturing system 2300 and / or the acoustic core construction system 2302.

[0172] Acoustic core manufacturing system 2300 and / or acoustic core construction system 2302 may include tool assembly production system 2301 and / or tool assembly construction system 2303. Additionally or in the alternative, tool assembly production system 2301 and / or tool assembly construction system 2303 may include acoustic core manufacturing system 2300 and / or acoustic core construction system 2302. For example, acoustic core construction system 2302 and / or tool assembly construction system 2303 may be modules of a computing system. Tool assembly production system 2301 may be configured to produce tool assembly 2000 and / or one or more forming tools used in a tool assembly. Tool assembly construction system 2303 may include a computer-readable medium configured to determine a configuration of tool assembly 2000 and / or one or more forming tools 2002 used with tool assembly 2000. Additionally or in the alternative, a computer-readable medium may be configured to operate tool assembly construction system 2303 and / or tool assembly production system 2301.

[0173] Acoustic core manufacturing system 2300 and / or acoustic core construction system 2302 may include a user interface 2304 configured to allow a user to operate acoustic core manufacturing system 2300 and / or acoustic core construction system 2302. Additionally, or in the alternative, tool assembly production system 2301 and / or tool assembly construction system 2303 may include a user interface 2304 configured to allow a user to operate tool assembly production system 2301 and / or tool assembly construction system 2303.

[0174] In some embodiments, the acoustic core manufacturing system 2300 may include a manufacturing machine 2306 configured to manufacture the acoustic core 200 according to the configuration provided by the acoustic core construction system 2302. The acoustic core manufacturing system 2300 may be configured to manufacture the acoustic core 200 using a tool assembly 2000 configured according to the present disclosure. The acoustic core manufacturing system 2300 and / or the acoustic core construction system 2302 may include a management system 2308 configured to provide enterprise-level control for one or more elements of the acoustic core manufacturing system 2300 and / or for one or more elements of the acoustic core construction system 2302. The various elements of the acoustic core manufacturing system 2300 and / or the various elements of the acoustic core construction system 2302 may be communicatively coupled to each other via wired or wireless communication links 2310 as part of a communication network 2312.

[0175] In some embodiments, the tool assembly production system 2301 and / or the tool assembly construction system 2303 may include a management system 2308 configured to provide enterprise-level control for one or more elements of the tool assembly production system 2301 and / or for one or more elements of the tool assembly construction system 2303. The various elements of the tool assembly production system 2301 and / or the various elements of the tool assembly construction system 2303 may be communicatively coupled to each other via wired or wireless communication links 2310 as part of a communication network 2312.

[0176] The acoustic core construction system 2302 and / or the tool assembly construction system 2303 may include one or more computing devices 2314, which may be located locally or remotely relative to the user interface 2304, the manufacturing machine 2306, and / or the management system 2308. For example, the one or more computing devices may be located at an acoustic core development facility, which may include a physical facility and / or a cloud-based facility. The one or more computing devices 2314 may include one or more processors 2316 and one or more memory devices 2318. The one or more processors 2316 may include any suitable processing device, such as a microprocessor, a microcontroller, an integrated circuit, a logic device, and / or other suitable processing device.

[0177] The one or more memory devices 2318 may store information accessible by the one or more processors 2316, including computer executable instructions 2320 executable by the one or more processors 2316. The instructions 2320 may include any set of instructions that, when executed by the one or more processors 2316, cause the one or more processors 2316 to perform operations. In some embodiments, the instructions 2320 may be configured to cause the one or more processors 2316 to perform operations for which the acoustic core manufacturing system 2300, the acoustic core construction system 2302, the tool assembly production system 2301, the tool assembly construction system 2303, and / or the one or more computing devices 2314 are configured.

[0178] As used herein, the terms "processor" and "computer" and related terms (such as "processing device" and "computing device") are not limited to those integrated circuits known in the art as computers, but refer generally to microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated circuits, and other programmable circuits, and these terms are used interchangeably herein. In the embodiments described herein, the memory device 2318 may include, but is not limited to, non-transitory computer-readable media (such as random access memory (RAM)), computer-readable non-volatile media (such as hard disk drives, flash memory), and other memory devices. Alternatively, a floppy disk, a compact disk read-only memory (CD-ROM), a magneto-optical disk (MOD), and / or a digital versatile disk (DVD) may also be used.

[0179] As used herein, the term "non-transitory computer-readable medium" is intended to mean any tangible computer-based device implemented in any method or technology for short-term and long-term storage of information (e.g., computer-readable instructions, data structures, program modules and submodules, or other data in any device). The methods described herein may be encoded as executable instructions embodied in a tangible non-transitory computer-readable medium (including but not limited to storage devices and / or memory devices). Such instructions, when executed by a processor, cause the processor to perform at least a portion of the methods described herein. In addition, as used herein, the term "non-transitory computer-readable medium" includes all tangible computer-readable media, including but not limited to non-transitory computer storage devices, including but not limited to volatile and non-volatile media, and removable and non-removable media, such as firmware, physical and virtual storage devices, CD-ROMs, DVDs, and any other digital source, such as a network or the Internet, as well as digital means yet to be developed, with the sole exception of transient propagation signals.

[0180] Exemplary operations of the acoustic core manufacturing system 2300, the acoustic core construction system 2302, and / or the one or more computing devices 2314 may include determining a configuration of the acoustic core 200 and / or producing the acoustic core 200. The configuration of the acoustic core 200 may be determined using the acoustic core construction system 2302. Additionally, or in the alternative, the acoustic core 200 may be produced using a manufacturing machine 2306.

[0181] The acoustic core construction system 2302 may include one or more acoustic core construction modules 2322. The acoustic core construction system 2302 may utilize the acoustic core construction module 2322 to determine the construction of the acoustic core 200. Additionally, or in the alternative, the manufacturing machine 2306 may utilize the acoustic core construction module 2322 to produce the acoustic core 200. The one or more acoustic core construction modules 2322 may be implemented in hardware and / or software (including any non-transitory computer program product and / or cloud-based solution).

[0182] The acoustic core construction module 2322 may include proprietary modeling algorithms for determining the construction of the acoustic core 200 and / or producing the acoustic core 200. The proprietary algorithms may include tools for determining the effects of various constructions of resonant units and / or groups of resonant units on noise attenuation in various operating environments under given operating conditions. The proprietary algorithms may include tools for matching or grouping resonant units with each other in an array, for example, to provide a recognizable pattern that is repeated across at least a portion of the array of resonant units, including determining the construction of resonant units that are geometrically adapted to each other and / or tuned to attenuate resonant frequencies in complementary ranges. In addition, or in the alternative, the proprietary algorithms may include tools for grouping or aligning partitions to improve the constructability and mechanical integrity of the acoustic core.

[0183] For a corresponding range of resonant frequencies, the acoustic core construction module 2322 may additionally or alternatively include a proprietary modeling algorithm for determining the construction of a resonant unit (including a low frequency resonant unit, a high frequency resonant unit, and / or a mid-frequency resonant unit) that reduces the frequency. The acoustic core construction module 2322 may additionally or alternatively include a proprietary modeling algorithm for determining the resonant length of the resonant unit and / or comparing the resonant frequency to the nominal resonant unit. For example, the acoustic core construction module 2322 may determine the construction of a resonant unit that provides a desired resonant length that accommodates a given acoustic core height constraint. The acoustic core construction module 2322 may additionally or alternatively include a proprietary modeling algorithm for determining the construction of coupled resonant units, partitioned resonant units, tilted resonant units, and / or vertical resonant units. The acoustic core construction module 2322 may additionally or alternatively include a proprietary modeling algorithm for determining the construction of an acoustic screen 202 and / or back panel 204 accompanying the acoustic core 200, and / or the construction of a complete acoustic liner 100. Proprietary algorithms included in the acoustic core construction module 2322 may include finite element analysis tools, three-dimensional modeling tools, simulation modeling tools, and the like.

[0184] Exemplary operations of the tool assembly production system 2301, the tool assembly construction system 2303, and / or the one or more computing devices 2314 may include determining a configuration of the tool assembly 2000, and / or determining a configuration of one or more forming tools 2002 for use in the tool assembly 2000. Additionally, or in the alternative, exemplary operations may include producing the tool assembly 2000 and / or producing one or more forming tools 2002 for use in the tool assembly 2000. The configuration of the tool assembly 2000 and / or the configuration of the one or more forming tools 2002 may be determined using the tool assembly construction system 2303. Additionally, or in the alternative, the tool assembly 2000 and / or the one or more forming tools 2002 may be produced using a manufacturing machine 2306.

[0185] The tool assembly configuration system 2303 may include one or more tool assembly configuration modules 2323. The tool assembly configuration modules 2323 may be used by the tool assembly configuration system 2303 to determine the configuration of the tool assembly 2000 and / or the configuration of one or more forming tools 2002. Additionally, or in the alternative, the tool assembly configuration modules 2323 may be used by the tool production machine 2307 to produce the tool assembly 2000 and / or the one or more forming tools 2002. The one or more tool assembly configuration modules 2323 may be implemented in hardware and / or software (including any non-transitory computer program product and / or cloud-based solution).

[0186] The tool assembly configuration module 2323 may include a proprietary modeling algorithm for determining the configuration of the tool assembly 2000 and / or for determining the configuration of one or more forming tools 2002. Additionally, or in the alternative, the tool assembly configuration module 2323 may include a proprietary modeling algorithm for producing the tool assembly 2000 and / or for producing one or more forming tools 2002. The proprietary algorithm may include a tool for determining the configuration of the tool assembly 2000 and / or determining the configuration of one or more forming tools 2002 based at least in part on the determined configuration of the acoustic core 200 (e.g., based at least in part on the effects of various configurations of the resonant unit 206 and / or the resonant unit group 1200 on noise attenuation in various operating environments under given operating conditions). The proprietary algorithm may include a tool for determining a configuration of the tool assembly 2000 and / or the forming tool 2002 based at least in part on a determined matching or grouping of resonant elements in the array with one another, e.g., to provide a recognizable pattern that repeats across at least a portion of the array of resonant elements, including a determined configuration of resonant elements 206 that are geometrically adapted to one another and / or tuned to attenuate complementary ranges of resonant frequencies. Additionally, or in the alternative, the proprietary algorithm may include a tool for determining a configuration of the tool assembly 2000 and / or the forming tool 2002 based at least in part on the grouping or alignment of partitions, so as to improve the buildability and mechanical integrity of the acoustic core, and / or to improve the release of the acoustic core from the tool assembly 2000 and / or its forming tool 2002.

[0187] For the corresponding range of resonant frequencies, the tool assembly construction module 2323 may additionally or alternatively include a proprietary modeling algorithm for determining the construction of the tool assembly 2000 and / or the forming tool 2002, which is configured to produce resonant units of reduced frequency, including low frequency resonant units, high frequency resonant units, and / or mid-frequency resonant units. The tool assembly construction module 2323 may additionally or alternatively include a proprietary modeling algorithm for determining the construction of the tool assembly 2000 and / or the forming tool 2002, which is configured to produce an acoustic core 200, which includes a resonant unit 206 having a desired resonant length that accommodates a given acoustic core height constraint. Tool assembly construction module 2323 may additionally or alternatively include a proprietary modeling algorithm for determining the configuration of tool assembly 2000 and / or forming tool 2002, which is configured to generate coupled resonant units, partitioned resonant units, converging resonant units, diverging resonant units, tilted resonant units, and / or vertical resonant units. Tool assembly construction module 2323 may additionally or alternatively include a proprietary modeling algorithm for determining tool assembly 2000 and / or forming tool 2002, which is configured to produce an acoustic core having a curved profile (e.g., a convex curved profile and / or a concave curved profile). The tool assembly construction module 2323 may additionally or alternatively include proprietary modeling algorithms for determining a tool assembly 2000 and / or a forming tool 2002 configured to produce an acoustic screen 202 and / or a backing plate 204 accompanying an acoustic core 200, and / or a configuration of a complete acoustic liner 100. The proprietary algorithms included in the tool assembly construction module 2323 may include finite element analysis tools, three-dimensional modeling tools, simulation modeling tools, and the like.

[0188] The memory device 2318 may store data 2324 accessible by the one or more processors 2316. The data 2324 may include current or real-time data, past data, or a combination thereof. The data 2324 may be stored in a database 2326. As an example, the data 2324 may include data associated with or generated by the acoustic core manufacturing system 2300, the acoustic core construction system 2302, the user interface 2304, the manufacturing machine 2306, the management system 2308, the one or more computing devices 2314, and / or the one or more acoustic core construction modules 2322. The data 2324 may also include other data sets, parameters, outputs, information associated with the acoustic core manufacturing system 2300 and / or the acoustic core construction system 2302. In addition, or in the alternative, the data 2324 may include other data sets, parameters, outputs, information associated with the tool assembly production system 2301 and / or the tool assembly construction system 2303. The data 2324 including the database 2326 and / or other data sets, parameters, outputs, information may be used by one or more acoustic core construction modules 2322 to perform the operations for which they are configured.

[0189] The one or more computing devices 2314 may also include a communication interface 2328, which may be used to communicate with a communication network. The communication interface 2328 may include any suitable components for interfacing with one or more networks, including, for example, a transmitter, a receiver, a port, a controller, an antenna, and / or other suitable components. The communication interface 2328 may allow the one or more computing devices 2314 to communicate with the user interface 2304, the manufacturing machine 2306, the tool production machine 2307, and / or the management system 2308. The communication network 2312 may include, for example, a local area network (LAN), a wide area network (WAN), a SATCOM network, a VHF network, a HF network, a Wi-Fi network, a WiMAX network, a gatelink network, and / or any other suitable communication network 2312 for sending and / or receiving data messages. The communication lines 2310 of the communication network 2312 may include a data bus or a combination of wired and / or wireless communication links.

[0190] Management system 2308 may include server 2330 and / or data warehouse 2332. As an example, at least a portion of data 2324 may be stored in data warehouse 2332, and server 2330 may be configured to transmit data 2324 from data warehouse 2332 to one or more computing devices 2314, and / or receive data 2324 from one or more computing devices 2314 and store received data 2324 in data warehouse 2332 for further purposes. Server 2330 and / or data warehouse 2332 may be implemented as part of acoustic core manufacturing system 2300 and / or acoustic core construction system 2302. Additionally, or in the alternative, server 2330 and / or data warehouse 2332 may be implemented as part of tool assembly production system 2301 and / or tool assembly construction system 2303.

[0191] Any suitable additive manufacturing technology may be used to manufacture various aspects of the presently disclosed acoustic liner 100. Exemplary additive manufacturing technologies include, but are not limited to: directed energy deposition (DED) systems, such as chemical vapor deposition (CVD) systems, laser metal deposition (LMD) systems, directed metal deposition (DMD) systems, laser engineered net shaping (LENS) systems, electron beam additive melting (EBAM) systems, or rapid plasma deposition (RPD) systems; powder bed fusion (PBF) systems, such as direct metal laser melting (DMLM) systems, electron beam melting (EBM) systems, directed metal laser sintering (DMLS) systems, selective laser melting (SLM) systems; systems or selective laser sintering (SLS) systems; laminated object manufacturing (LOM) systems, such as ultrasonic additive manufacturing (UAM) systems; master extrusion (ME) systems, such as fused deposition modeling (FDM) systems or fused filament fabrication (FFF) systems; material jetting (MJ) systems, such as smooth curvature printing (SCP) systems, multi-jet modeling (MJM) systems; and 3D printing, such as by inkjet and laser jetting, including binder jetting (BJ) systems; photopolymer jetting (PJ) systems, stereolithography (SLA) systems and hybrid processing (HP).

[0192] Other suitable techniques that may be used to manufacture various aspects of the presently disclosed acoustic liner 100 include, but are not limited to, forming (e.g., rolling, stamping, bonding, etc.), injection molding or compression molding, extrusion (e.g., sheet extrusion), subtractive manufacturing (e.g., machining, drilling, laser cutting, etc.), forging or casting, and combinations thereof, or any other manufacturing technique.

[0193] In the case of material extrusion, for example, using a fused deposition modeling (FDM) system or a fused filament manufacturing (FFF) system, additive manufacturing materials can be provided in the form of filaments. For example, the filaments can include thermoplastic materials, metal materials, or ceramic materials. In the case of material jetting (MJ), additive manufacturing materials can include photosensitive materials, such as thermosetting materials. Photosensitive materials can be provided in the form of liquids, gels, etc., and can be cured when exposed to an additive energy source (such as ultraviolet light). In the case of binder jetting (BJ), additive manufacturing materials can include binder materials sprayed into a bed of powdered materials. Binder materials can be applied in the form of liquids, gels, etc. Exemplary binder materials include thermosetting materials or thermoplastic materials. Exemplary powder materials for binder jetting (BJ) can include, for example, metals or metal alloys, thermoplastic materials, and ceramics. In the case of directed energy deposition (DED), additive manufacturing materials can be provided in the form of wires, filaments, or powders. Exemplary materials for directed energy deposition (DED) can include, for example, metals or metal alloys, thermoplastic materials, and ceramics.

[0194] Additive manufacturing techniques that use additive energy beams to solidify (e.g., melt, fuse, solidify, etc.) amorphous additive manufacturing materials (e.g., powders, liquids, gels, etc.) are sometimes referred to herein as additive energy techniques. Additive energy techniques include powder bed fusion (PBF) (e.g., selective laser sintering (SLS), direct metal laser sintering (SLM), laser melting (LM), electron beam melting (EBM), selective heat sintering (SHS), multi-jet melting (MJF), etc.) and photopolymerization curing techniques (vatphotopolymerization) (e.g., stereolithography equipment (SLA), digital light processing (DLP), scanning, rotation and selective photocuring (3SP), continuous liquid interface production (CLIP), etc.). In the case of powder bed fusion (PBF), additive manufacturing materials can be provided in the form of powders. Exemplary powder materials for powder bed fusion (PBF) can include, for example, metals or metal alloys, polymeric materials (e.g., thermosetting materials and / or thermoplastic materials) and ceramics. In the case of photopolymerization curing techniques, additive manufacturing materials can include photosensitive materials. Exemplary photosensitive materials that can be used with additive manufacturing techniques (e.g., additive material techniques or additive energy techniques) include formulations containing, for example, binders, monomers, and photoinitiators. Exemplary binders include styrene, methacrylates, vinyl alcohol, olefins, glycerol, and propylene. Exemplary monomers include acrylic acid, methacrylic acid, isodecyl acrylate, and N-vinyl pyrrolidone. Exemplary photoinitiators include free radical photoinitiators (e.g., isopropylthioxanthone, benzophenone, and 2,2-azobisisobutyronitrile), and cationic photoinitiators (e.g., diaryliodonium salts and triarylsulfonium salts).

[0195] The acoustic core 200 can be formed of a polymeric material (e.g., a thermoplastic, a thermosetting, or an elastomeric polymer material), a synthetic fiber, a metal alloy, or a composite material, and can be formed separately from the acoustic shield 202 and / or the backing plate 204 or simultaneously as part of an additive manufacturing technique or any other suitable process. Alternatively, the acoustic core 200 can be secured between the acoustic shield 202 and the backing plate 204 using an adhesive process. For example, heat, sonic waves, or electric welding processes can be used. As another example, diffusion bonding can be used. Alternatively, an adhesive formulation (such as a thermosetting or pressure-sensitive adhesive or adhesive tape) can be used to secure the acoustic core 200 in place. In addition, the acoustic core 200 can be formed of any other suitable techniques and / or materials, all of which are within the scope of the present disclosure.

[0196] Exemplary polymer materials can include thermoplastic materials and / or thermosetting materials. Exemplary thermosetting materials include, for example, epoxy resins, resins, acrylic resins, phenolic resins, polyesters, polyurethanes, polyimides, polyamide-imide (PAI), polysiloxane bismaleimide, cyanate esters, phenolic resins, benzoxazine, phthalonitrile. Exemplary thermoplastic materials include, for example, acrylonitrile butadiene styrene (ABS), acrylonitrile styrene acrylate (ASA), styrene acrylonitrile (SAN), polyesters, polyamide-imide (PAI), polyetherimide (PEI), polyphenyl sulfone (PPSF), polycarbonate (PC), polylactic acid (PLA), high impact polystyrene (HIPS), thermoplastic polyurethane (TPU), aliphatic polyamide (nylon), polyaryletherketone (PAEK), polyetherketoneketone (PEKK) or polyetheretherketone (PEEK) and combinations thereof.

[0197] Exemplary synthetic fibers include extruded polymer filaments such as polyetherimide (PEI), acrylonitrile styrene acrylate (ASA), polyetheretherketone (PEEK), polycarbonate, acrylonitrile, acrylonitrile-butadiene-styrene, aramid fibers, meta-aramid fibers, para-aramid fibers, polyethylene fibers, rayon, polyester or nylon, and combinations of these.

[0198] Exemplary metal alloys include aluminum alloys, steel alloys, titanium alloys, or nickel alloys (eg, superalloys such as austenitic nickel-chromium based superalloys), and combinations of these.

[0199] Exemplary composite materials include ceramic matrix composite (CMC) materials and / or polymer matrix composite (PMC) materials. CMC materials include ceramic matrix materials and reinforcing fibers or cloth. Exemplary ceramic matrix materials include silicon carbide (SiC) and / or carbon (C). Exemplary CMC materials include carbon fiber reinforced carbon (C / C), carbon fiber reinforced silicon carbide (C / SiC) or silicon carbide reinforced silicon carbide (SiC / SiC). PMC materials include polymer matrix materials and reinforcing fibers or cloth. Exemplary PMC materials include fiber reinforced plastics and advanced composite materials. Exemplary polymer matrix materials include thermosetting materials, such as epoxy resins, phenolic resins, polyurethanes, polyimides, bismaleimides, cyanates, phenolic resins, benzoxazine, phthalonitrile. In some embodiments, polyimides may be particularly suitable. Exemplary polyimides include phenylethynyl terminated imide (PETI) oligomers, 2,2'-dimethylbenzidine based on biphenyl dianhydride, and ultra-high temperature HFPE. In some embodiments, exemplary polyimides may include end caps, such as 4-phenylethynylphthalic anhydride (PEPA) and / or asymmetric oxydiphthalic anhydride (a-ODPA) end caps.

[0200] Exemplary reinforcing fibers or cloths that can be used for CMC or PMC materials include carbon fibers, ceramic fibers, glass fibers, graphite fibers, and aramid fibers. Exemplary reinforcing fibers include monofilaments, yarns, chopped whiskers or fibers, and / or particles. In certain embodiments, ceramic fibers can be formed by materials (such as silicon carbide (SiC), carbon fibers (C), sapphire, aluminum silicate and / or oxides of Si, Al, Zr, Y, and combinations thereof). Reinforcing fibers can additionally include inorganic fillers, such as silicon dioxide, quartz, pyrophyllite, wollastonite, mica, talc, kyanite and / or montmorillonite, and combinations thereof.

[0201] The present disclosure provides a variety of configurations of the resonant unit 206 that may be included in the acoustic core 200. It should be understood that many additional configurations are within the scope of the present disclosure. By way of example and not limitation, further aspects of the present disclosure are provided by the subject matter of the following clauses:

[0202] 1. An acoustic lining, comprising: an acoustic core, the acoustic core comprising an array of resonance units, wherein corresponding resonance units in the resonance units comprise one or more unit walls and a resonance space defined by the one or more unit walls, and wherein the array of resonance units comprises: a plurality of partitioned resonance units, corresponding partitioned resonance units in the plurality of partitioned resonance units comprise partition members integrally formed with at least one of the corresponding one or more unit walls and transverse to the corresponding resonance space, wherein at least one surface of the partition member has an interface angle, and the interface angle is inclined or perpendicular to a plane parallel to the top surface and / or bottom surface of the array of resonance units.

[0203] 2. An acoustic liner according to any clause herein, wherein the interface angle is 5 degrees to 90 degrees determined from a plane parallel to the bottom surface and / or the top surface of the resonant unit array.

[0204] 3. An acoustic liner according to any clause herein, wherein the partition member comprises at least one support member integrally formed with at least one of the one or more cell walls.

[0205] 4. An acoustic liner according to any clause herein, wherein the partitions intersect the corresponding resonant spaces with a substantially uniform cross-sectional thickness.

[0206] 5. An acoustic liner according to any item described herein, wherein the partition member includes at least one surface having an interface angle of approximately 0 degrees determined from a plane parallel to the bottom surface and / or top surface of the array of resonant units.

[0207] 6. An acoustic liner according to any item described herein, wherein the partition member intersects the corresponding resonance space with a substantially uniform cross-sectional thickness, and wherein the partition member has an interface angle of approximately 90 degrees determined from a plane parallel to the bottom surface and / or the top surface.

[0208] 7. An acoustic liner according to any item described herein, wherein the partition members corresponding to at least some of the multiple resonant units include one or more partition apertures, and the one or more partition apertures define a passage between the upper resonant space and the lower resonant space.

[0209] 8. An acoustic liner according to any item described herein, wherein the one or more partitioned apertures defining the passage between the upper resonant space and the lower resonant space include an array of partitioned apertures defining an array of passages between the upper resonant space and the lower resonant space.

[0210] 9. An acoustic liner according to any item described herein, comprising: a plurality of inclined resonant units, wherein a corresponding inclined resonant unit among the plurality of inclined resonant units comprises at least one unit wall having one or more wall openings, wherein the one or more wall openings define a passage between a previous resonant space and a subsequent resonant space; wherein the plurality of inclined resonant units have a unit angle of 5 degrees to 90 degrees determined from a plane parallel to the bottom surface and / or the top surface of the resonant unit array.

[0211] 10. An acoustic liner according to any clause herein, wherein the array of resonance units comprises: a plurality of converging resonance units and / or a plurality of diverging resonance units.

[0212] 11. An acoustic liner according to any item described herein, comprising: a plurality of coupled resonant units, wherein a corresponding coupled resonant unit in the plurality of coupled resonant units comprises at least one unit wall, wherein the at least one unit wall has one or more wall openings defining a passage between a previous resonant space and a subsequent resonant space.

[0213] 12. An acoustic liner according to any item described herein, comprising: wherein the cross-sectional dimensions of the one or more wall openings defining the passage between the previous resonant space and the subsequent resonant space are smaller than the cross-sectional dimensions of the previous resonant space and / or the cross-sectional dimensions of the subsequent resonant space, and the cross-sectional dimensions of the previous resonant space and / or the cross-sectional dimensions of the subsequent resonant space are determined adjacent to the one or more wall openings.

[0214] 13. An acoustic liner according to any clause herein, wherein the one or more wall apertures defining the passage between the previous resonant space and the subsequent resonant space include an array of partitioned apertures defining an array of passages between the previous resonant space and the subsequent resonant space.

[0215] 14. An acoustic liner according to any clause herein, wherein the one or more wall apertures defining the passage between the preceding resonant space and the subsequent resonant space are provided proximal to the bottom surface.

[0216] 15. An acoustic liner according to any item described herein, wherein the resonance unit array includes: a plurality of intermediate frequency resonance units, and a corresponding intermediate frequency resonance unit in the plurality of intermediate frequency resonance units is located between corresponding at least two coupled resonance units in the plurality of coupled resonance units.

[0217] 16. An acoustic liner according to any item described herein, wherein the passage between the previous resonance space and the subsequent resonance space crosses the corresponding intermediate frequency resonance unit among the multiple intermediate frequency resonance units, and the corresponding intermediate frequency resonance unit among the multiple intermediate frequency resonance units includes a partition separating the passage from the intermediate resonance space.

[0218] 17. An acoustic liner according to any clause herein, wherein at least some of the resonant units have cross-sectional areas different from each other, the cross-sectional areas being determined along a plane parallel to the top surface and / or the bottom surface.

[0219] 18. An acoustic liner according to any item described herein, wherein the array of resonant units includes one or more unit walls, and the one or more unit walls are aligned along a linear or curved trajectory extending through multiple resonant units; and / or wherein the array of resonant units includes one or more partitions, and the one or more partitions are aligned along a linear or curved trajectory extending through multiple resonant units.

[0220] 19. An acoustic lining according to any clause herein, comprising: an acoustic screen, which is at least partially formed integrally with the corresponding one or more unit walls; and / or a back panel, which is at least partially formed integrally with the corresponding one or more unit walls.

[0221] 20. An acoustic liner according to any clause herein, wherein the array of resonant units is produced using additive manufacturing techniques.

[0222] 21. An acoustic liner comprising an acoustic core as described in any clause herein.

[0223] 22. An acoustic core, comprising: an array of resonance units, wherein corresponding resonance units in the resonance units include one or more unit walls and a resonance space defined by the one or more unit walls, and wherein the array of resonance units includes: a plurality of coupled resonance units, wherein corresponding coupled resonance units in the plurality of coupled resonance units include at least one unit wall, wherein the at least one unit wall has one or more wall openings defining a passage between a previous resonance space and a subsequent resonance space; wherein the cross-sectional dimensions of the one or more wall openings defining the passage between the previous resonance space and the subsequent resonance space are smaller than the cross-sectional dimensions of the previous resonance space and / or the cross-sectional dimensions of the subsequent resonance space, and the cross-sectional dimensions of the previous resonance space and / or the cross-sectional dimensions of the subsequent resonance space are determined adjacent to the one or more wall openings.

[0224] 23. An acoustic core according to any clause herein, wherein the one or more wall apertures defining the passage between the previous resonant space and the subsequent resonant space comprise an array of partitioned apertures defining an array of passages between the previous resonant space and the subsequent resonant space.

[0225] 24. An acoustic core according to any clause herein, wherein the one or more wall apertures defining the passage between the preceding resonance space and the subsequent resonance space are provided proximal to the bottom surface.

[0226] 25. An acoustic core according to any item described herein, wherein the array of resonance units includes: a plurality of intermediate frequency resonance units, and a corresponding intermediate frequency resonance unit among the plurality of intermediate frequency resonance units is positioned to be at least partially adjacent to at least one of the plurality of coupled resonance units, and / or at least partially surrounded by at least one of the plurality of coupled resonance units.

[0227] 26. An acoustic core according to any item described herein, wherein the passage between the previous resonance space and the subsequent resonance space crosses the corresponding intermediate frequency resonance unit among the multiple intermediate frequency resonance units, and the corresponding intermediate frequency resonance unit among the multiple intermediate frequency resonance units includes a partition separating the passage from the intermediate resonance space.

[0228] 27. An acoustic core according to any clause herein, wherein the partition separating the passage from the intermediate resonant space delimits an intermediate resonant space defining at least a portion of the passage between the preceding resonant space and the subsequent resonant space.

[0229] 28. An acoustic core according to any clause herein, wherein the mid-frequency resonance unit comprises a first cell wall, the first cell wall converging with and / or adjoining a second cell wall.

[0230] 29. An acoustic core according to any clause herein, wherein the array of resonance units comprises: a plurality of convergent resonance units and / or a plurality of divergent resonance units.

[0231] 30. An acoustic core according to any clause herein, wherein the array of resonant units comprises at least some tilted resonant units.

[0232] 31. An acoustic core according to any clause herein, wherein the inclined resonance unit has a unit angle of 5 to 90 degrees determined from a plane parallel to the bottom surface and / or top surface of the resonance unit array.

[0233] 32. An acoustic core according to any clause herein, comprising: a plurality of partitioned resonance units, wherein corresponding partitioned resonance units among the plurality of partitioned resonance units comprise partition members that cross the corresponding resonance space, and wherein the partition members are integrally formed with at least one of the corresponding one or more unit walls.

[0234] 33. An acoustic core according to any item described herein, wherein the partition element crosses the corresponding resonance space, wherein at least one surface of the partition element has an interface angle, and the interface angle is inclined or perpendicular to a plane parallel to the top and / or bottom surface of the resonant unit array.

[0235] 34. An acoustic core according to any clause herein, wherein the interface angle is 5 to 90 degrees determined from a plane parallel to a bottom surface and / or a top surface of the array of resonant units.

[0236] 35. An acoustic core according to any clause herein, wherein the partition member comprises at least one support member integrally formed with at least one of the one or more cell walls.

[0237] 36. An acoustic core according to any clause herein, wherein the partitions intersect the corresponding resonant spaces with a substantially uniform cross-sectional thickness.

[0238] 37. An acoustic core according to any item described herein, wherein the partition element intersects the corresponding resonance space with a substantially uniform cross-sectional thickness, and wherein the partition element has an interface angle of approximately 0 degrees determined from a plane parallel to the bottom surface and / or the top surface.

[0239] 38. An acoustic core according to any clause herein, wherein the partitions corresponding to at least some of the plurality of resonant units include one or more partition apertures defining a passage between the upper resonant space and the lower resonant space.

[0240] 39. An acoustic core according to any clause herein, wherein at least some of the resonant units have cross-sectional areas different from each other, the cross-sectional areas being determined along a plane parallel to the top surface and / or the bottom surface.

[0241] 40. An acoustic core according to any item described herein, wherein the array of resonant units includes one or more unit walls, and the one or more unit walls are aligned along a linear or curved trajectory extending through multiple resonant units; and / or wherein the array of resonant units includes one or more partitions, and the one or more partitions are aligned along a linear or curved trajectory extending through multiple resonant units.

[0242] 41. An acoustic core according to any clause herein, wherein the array of resonant units is produced using additive manufacturing techniques.

[0243] 42. An acoustic core, comprising: a resonance unit array, comprising: a plurality of coupled resonance units, wherein corresponding coupled resonance units among the plurality of coupled resonance units define a previous resonance space and a subsequent resonance space, and comprising at least one unit wall having one or more wall openings, wherein the one or more wall openings define a passage between the previous resonance space and the subsequent resonance space; and a plurality of high-frequency resonance units, wherein the plurality of high-frequency resonance units respectively define high-frequency resonance spaces, and corresponding high-frequency resonance units among the plurality of high-frequency resonance units are matched with corresponding coupled resonance units among the plurality of coupled resonance units.

[0244] 43. An acoustic core according to any item herein, wherein the cross-sectional dimensions of the one or more wall openings defining the passage between the previous resonant space and the subsequent resonant space are smaller than the cross-sectional dimensions of the previous resonant space and / or the cross-sectional dimensions of the subsequent resonant space, and the cross-sectional dimensions of the previous resonant space and / or the cross-sectional dimensions of the subsequent resonant space are determined adjacent to the one or more wall openings.

[0245] 44. The acoustic core according to any clause herein, wherein the plurality of coupled resonance units and / or the plurality of high frequency resonance units comprise a plurality of tilted resonance units.

[0246] 45. An acoustic core according to any item described herein, wherein a corresponding coupled resonant unit among the plurality of coupled resonant units has an aperture reduction factor from 0.2 to less than 1.0, and the aperture reduction factor relates the cross-sectional dimension of the one or more wall apertures to the cross-sectional dimension of the previous resonant space and / or the cross-sectional dimension of the subsequent resonant space according to the following relationship: a=c(1-β), where β is the aperture reduction factor, "a" is the cross-sectional dimension of the one or more wall apertures, and "c" is the cross-sectional dimension of the previous resonant space and / or the cross-sectional dimension of the subsequent resonant space.

[0247] 46. ​​The acoustic core according to any item described in this document comprises: a plurality of partitioned resonant units, wherein corresponding partitioned resonant units among the plurality of partitioned resonant units comprise partitioning members that cross the corresponding resonant space of the partitioned resonant units at an interface angle, wherein the interface angle is inclined or perpendicular to a plane parallel to the top surface and / or bottom surface of the resonant unit array.

[0248] 47. An acoustic core according to any item described herein, wherein the subsequent resonance space of at least some of the multiple coupled resonance units defines the lower resonance space of at least some of the multiple partitioned resonance units, and / or wherein at least some of the high-frequency resonance units define the upper resonance space of at least some of the multiple partitioned resonance units.

[0249] 48. The acoustic core according to any item described in this document comprises: a plurality of intermediate frequency resonance units, each of which defines an intermediate frequency resonance space, wherein corresponding intermediate frequency resonance units in the plurality of intermediate frequency resonance units are matched with corresponding coupled resonance units in the plurality of coupled resonance units and / or corresponding high frequency resonance units in the plurality of high frequency resonance units, wherein at least some of the intermediate frequency resonance units define an upper resonance space of at least some of the plurality of partitioned resonance units.

[0250] 49. An acoustic core, comprising: a resonance unit array, the resonance unit array comprising a plurality of resonance unit groups, corresponding resonance unit groups in the resonance unit groups comprising a plurality of resonance units, at least some of the plurality of resonance units comprising: partitioned resonance units, the partitioned resonance units comprising convergent resonance units and divergent resonance units, the convergent resonance units and the divergent resonance units being defined by a plurality of unit walls integrally formed with each other and partition members integrally formed with the plurality of unit walls, the partition members at least partially defining the convergent resonance units and the divergent resonance units; wherein the convergent resonance units define an upper resonance space defined by the partition members and the top surface of the resonance unit array, and wherein the divergent resonance units define a lower resonance space defined by the partition members and the bottom surface of the resonance unit array.

[0251] 50. An acoustic core according to any item described herein, wherein at least some of the multiple resonance units include: divergent resonance units, which are defined by the top surface and the bottom surface; and / or convergent resonance units, which are defined by the top surface and the bottom surface.

[0252] 51. An acoustic core according to any clause herein, wherein the acoustic core has a curved profile defined by the top surface and / or the bottom surface.

[0253] 52. An acoustic core according to any clause herein, wherein the curvilinear profile comprises a convex curvilinear profile and / or a concave curvilinear profile.

[0254] 53. An acoustic core according to any item described herein, wherein the array of resonance units includes a plurality of divergent resonance units defined by the top surface and the bottom surface at a position where the acoustic core has a convex curve profile; and / or wherein the array of resonance units includes a plurality of convergent resonance units defined by the top surface and the bottom surface at a position where the acoustic core has a concave curve profile.

[0255] 54. An acoustic core according to any item described herein, wherein at least some of the multiple resonance units include: a coupling resonance unit, the coupling resonance unit defines a coupling resonance space, the coupling resonance space includes a previous resonance space and a subsequent resonance space, and the coupling resonance unit includes at least one unit wall, the at least one unit wall has one or more wall openings defining a passage between the previous resonance space and the subsequent resonance space; wherein the coupling resonance unit is constructed as a divergent resonance unit, the coupling resonance unit is located at a portion of the acoustic core having a concave curve profile; or wherein the coupling resonance unit is constructed as a convergent resonance unit, the coupling resonance unit is located at a portion of the acoustic core having a convex curve profile.

[0256] 55. The acoustic core according to any clause herein, wherein the converging resonance unit is constructed as a high-frequency resonance unit defining a high-frequency resonance space, and the high-frequency resonance unit is matched with the coupling resonance unit.

[0257] 56. An acoustic core according to any item described herein, wherein at least some of the multiple resonance units include: a mid-frequency resonance unit, the mid-frequency resonance unit defines a mid-frequency resonance space, the mid-frequency resonance space is defined by the top surface and an additional partition, the additional partition separates the mid-frequency resonance space from the coupled resonance space; wherein the mid-frequency resonance unit is constructed as a convergent resonance unit.

[0258] 57. An acoustic core according to any item described herein, wherein the converging resonance unit presents a convergence angle from 0.5 degrees to 30 degrees relative to the longitudinal axis of the converging resonance unit; and / or wherein the diverging resonance unit presents a convergence angle from -0.5 degrees to -30 degrees relative to the longitudinal axis of the diverging resonance unit.

[0259] 58. An acoustic core according to any clause herein, wherein the acoustic core comprises an injection molded acoustic core, or wherein the acoustic core comprises a press-formed acoustic core, or wherein the acoustic core comprises an additively manufactured acoustic core.

[0260] 59. An acoustic core according to any item described herein, wherein the converging resonance unit is at least partially realized by the cross-sectional thickness of one or more cell walls and / or at least partially by the angle or orientation of one or more cell walls; and / or wherein the diverging resonance unit is at least partially realized by the cross-sectional thickness of one or more cell walls and / or at least partially by the angle or orientation of one or more cell walls.

[0261] 60. A method for making an acoustic core, the method comprising: determining the construction of an acoustic core including an array of resonance units using an acoustic core construction system, wherein determining the construction of the acoustic core comprises: determining the construction of a plurality of coupled resonance units, wherein corresponding coupled resonance units among the plurality of coupled resonance units define a previous resonance space and a subsequent resonance space, and include at least one unit wall having one or more wall openings, wherein the one or more wall openings define a passage between the previous resonance space and the subsequent resonance space; and determining the construction of a plurality of high-frequency resonance units respectively defining high-frequency resonance spaces, wherein corresponding high-frequency resonance units among the plurality of high-frequency resonance units are matched with corresponding coupled resonance units among the plurality of coupled resonance units.

[0262] 61. A method according to any item herein, wherein the cross-sectional dimensions of the one or more wall apertures defining the passage between the previous resonant space and the subsequent resonant space are smaller than the cross-sectional dimensions of the previous resonant space and / or the cross-sectional dimensions of the subsequent resonant space, and the cross-sectional dimensions of the previous resonant space and / or the cross-sectional dimensions of the subsequent resonant space are determined adjacent to the one or more wall apertures.

[0263] 62. The method according to any item in this document includes: determining the resonant frequency of low-frequency sound waves that are expected to be attenuated, and tuning the multiple coupled resonant units to the resonant frequency of the low-frequency sound waves that are expected to be attenuated, wherein the resonant length of the corresponding coupled resonant unit in the multiple coupled resonant units exceeds the height of the acoustic core; and / or determining the resonant frequency of high-frequency sound waves that are expected to be attenuated, and tuning the multiple high-frequency resonant units to the resonant frequency of the high-frequency sound waves that are expected to be attenuated, wherein the resonant length of the corresponding high-frequency resonant unit in the multiple high-frequency resonant units exceeds the height of the corresponding high-frequency resonant unit.

[0264] 63. A method according to any item herein, wherein the resonant length of a corresponding coupled resonant unit among the plurality of coupled resonant units exceeds the height of the acoustic core, at least in part by defining the cross-sectional dimension of the one or more wall openings of the passage between the previous resonant space and the subsequent resonant space being smaller than the cross-sectional dimension of the previous resonant space and / or the cross-sectional dimension of the subsequent resonant space.

[0265] 64. A method according to any item herein, wherein determining the configuration of the plurality of coupled resonant units comprises: determining the cross-sectional dimensions of the one or more wall apertures defining the passage between the previous resonant space and the subsequent resonant space of a corresponding coupled resonant unit among the plurality of coupled resonant units based at least in part on an aperture reduction factor; and / or determining the cross-sectional dimensions of the previous resonant space and / or the cross-sectional dimensions of the subsequent resonant space of a corresponding coupled resonant unit among the plurality of coupled resonant units based at least in part on an aperture reduction factor; wherein the aperture reduction factor is determined at least in part based on a relationship between the aperture reduction factor and a resonant frequency of a corresponding coupled resonant unit among the plurality of coupled resonant units.

[0266] 65. A method according to any item herein, wherein determining the configuration of the plurality of coupled resonant units comprises determining an aperture reduction factor of a corresponding coupled resonant unit in the plurality of coupled resonant units, the aperture reduction factor being determined at least in part based on a relationship between the aperture reduction factor and a resonant frequency of the corresponding coupled resonant unit in the plurality of coupled resonant units.

[0267] 66. A method according to any clause herein, wherein the relationship between the aperture reduction factor and the resonant frequency of a corresponding coupled resonant unit in the plurality of coupled resonant units comprises a resonant frequency that decreases as the aperture reduction factor increases.

[0268] 67. A method according to any clause herein, wherein the determined orifice reduction factor is from 0.5 to less than 1.0.

[0269] 68. A method according to any item herein, wherein the determined orifice reduction factor relates the cross-sectional dimension of the one or more wall orifices to the cross-sectional dimension of the previous resonant space and / or the cross-sectional dimension of the subsequent resonant space according to the following relationship: a=c(1-β), where β is the orifice reduction factor, "a" is the cross-sectional dimension of the one or more wall orifices, and "c" is the cross-sectional dimension of the previous resonant space and / or the cross-sectional dimension of the subsequent resonant space.

[0270] 69. A method according to any item herein, wherein the relationship between the aperture reduction factor and the resonant frequency of a corresponding coupled resonant unit in the plurality of coupled resonant units includes a non-linear region, and wherein the determined aperture reduction factor corresponds to the non-linear region.

[0271] 70. A method according to any item herein, wherein determining the structure of the acoustic core includes: determining the structure of a plurality of partitioned resonant units, a corresponding partitioned resonant unit among the plurality of partitioned resonant units including a partitioning element that crosses the corresponding resonant space of the partitioned resonant unit, wherein at least one surface of the partitioning element has an interface angle, and the interface angle is inclined or perpendicular to a plane parallel to the top surface and / or bottom surface of the resonant unit array.

[0272] 71. A method according to any item herein, wherein the subsequent resonance space of at least some of the multiple coupled resonance units defines a lower resonance space of at least some of the multiple partitioned resonance units; and / or wherein the high-frequency resonance space of at least some of the high-frequency resonance units defines an upper resonance space of at least some of the multiple partitioned resonance units.

[0273] 72. A method according to any item of the present invention, wherein the plurality of coupled resonant units includes a plurality of tilted resonant units, wherein the plurality of tilted resonant units have a unit angle of 5 degrees to 90 degrees determined from a plane parallel to the bottom surface and / or the top surface of the resonant unit array.

[0274] 73. A method according to any clause herein, wherein the array of resonance units comprises: a plurality of convergent resonance units and / or a plurality of divergent resonance units.

[0275] 74. A method according to any item herein, wherein the corresponding high-frequency resonant unit among the multiple high-frequency resonant units that matches the corresponding coupled resonant unit among the multiple coupled resonant units includes the corresponding high-frequency resonant unit among the multiple high-frequency resonant units that is geometrically adapted to the corresponding coupled resonant unit among the multiple coupled resonant units.

[0276] 75. A method according to any item herein, wherein determining the structure of the acoustic core includes: determining the structure of multiple intermediate frequency resonance units that respectively define intermediate frequency resonance spaces, corresponding intermediate frequency resonance units in the multiple intermediate frequency resonance units are matched with corresponding coupled resonance units in the multiple coupled resonance units and / or corresponding high frequency resonance units in the multiple high frequency resonance units.

[0277] 76. The method according to any item herein comprises: determining the resonant frequency of the intermediate frequency sound wave that is desired to be attenuated, and tuning the plurality of intermediate frequency resonance units to the resonant frequency of the intermediate frequency sound wave that is desired to be attenuated, wherein the resonant length of the corresponding intermediate frequency resonance unit in the plurality of intermediate frequency resonance units exceeds the height of the corresponding intermediate frequency resonance unit.

[0278] 77. The method according to any clause herein, wherein the intermediate frequency resonance space of at least some of the intermediate frequency resonance units defines an upper resonance space of at least some of the plurality of partitioned resonance units.

[0279] 78. A method according to any item of the present invention, wherein the array of resonant units includes one or more unit walls, and the one or more unit walls are aligned along a linear or curved trajectory extending through multiple resonant units; and / or wherein the array of resonant units includes one or more partitions, and the one or more partitions are aligned along a linear or curved trajectory extending through multiple resonant units.

[0280] 79. A method according to any clause herein, comprising: producing the acoustic core using additive manufacturing technology.

[0281] 80. A method according to any clause herein, wherein the method is configured to produce an acoustic core as described in any clause herein.

[0282] 81. A method according to any clause herein, wherein the method is configured to produce an acoustic liner as described in any clause herein.

[0283] 82. A method for forming an acoustic core, the method comprising: using a tool assembly construction system to determine the configuration of a tool assembly and / or the configuration of one or more forming tools used in the tool assembly; making the one or more forming tools and / or assembling a tool assembly including the one or more forming tools; and using the tool assembly including the one or more forming tools to form the acoustic core; wherein the tool assembly and / or the one or more forming tools have a configuration determined at least in part based on the configuration determined for the acoustic core; wherein the acoustic core comprises: an array of resonant units, the array of resonant units comprising a plurality of resonant unit groups, the resonant unit groups The corresponding resonance unit group in the array includes a plurality of resonance units, at least some of the plurality of resonance units include: a partitioned resonance unit, the partitioned resonance unit includes a convergent resonance unit and a divergent resonance unit, the convergent resonance unit and the divergent resonance unit are defined by a plurality of unit walls formed integrally with each other and a partitioning member formed integrally with the plurality of unit walls, the partitioning member at least partially defines the convergent resonance unit and the divergent resonance unit; wherein the convergent resonance unit defines an upper resonance space defined by the partitioning member and a top surface of the resonance unit array, and wherein the divergent resonance unit defines a lower resonance space defined by the partitioning member and a bottom surface of the resonance unit array.

[0284] 83. A method according to any clause herein, comprising: forming an acoustic liner at least in part by attaching an acoustic screen and the acoustic core to each other and / or at least in part by attaching a back panel and the acoustic screen to each other.

[0285] 84. A method according to any clause herein, comprising: forming the acoustic screen and / or forming the back panel.

[0286] 85. A method according to any clause herein, comprising: determining the configuration of the acoustic core using an acoustic core construction system.

[0287] 86. A method according to any item herein, wherein determining the structure of the acoustic core includes: determining the structure of a plurality of coupled resonant units, corresponding coupled resonant units among the plurality of coupled resonant units defining a previous resonant space and a subsequent resonant space, and including at least one unit wall having one or more wall openings, wherein the one or more wall openings define a passage between the previous resonant space and the subsequent resonant space; and determining the structure of a plurality of high-frequency resonant units respectively defining high-frequency resonant spaces, corresponding high-frequency resonant units among the plurality of high-frequency resonant units matching corresponding coupled resonant units among the plurality of coupled resonant units.

[0288] 87. A tool assembly for forming an acoustic core, the tool assembly comprising: a plurality of forming tools, a corresponding forming tool among the plurality of forming tools comprising a support member and a plurality of forming elements connected to the support member; wherein, when the plurality of forming tools are operated in proximity to each other, a mold cavity at least partially defined by the plurality of forming elements corresponds to an acoustic core to be formed by the tool assembly; wherein the acoustic core comprises: an array of resonance units, the array of resonance units comprising a plurality of resonance unit groups, a corresponding resonance unit group among the resonance unit groups comprising a plurality of resonance units, at least some of the plurality of resonance units comprising: partitioned resonance units, the partitioned resonance units comprising convergent resonance units and divergent resonance units, the convergent resonance units and the divergent resonance units being defined by a plurality of unit walls integrally formed with each other and partition members integrally formed with the plurality of unit walls, the partition members at least partially defining the convergent resonance units and the divergent resonance units; wherein the convergent resonance unit defines an upper resonance space defined by the partition members and a top surface of the resonance unit array, and wherein the divergent resonance unit defines a lower resonance space defined by the partition members and a bottom surface of the resonance unit array.

[0289] 88. A tool assembly according to any item described herein, wherein the plurality of forming elements have a draft angle such that the cross-sectional dimensions of the corresponding forming elements decrease from the cross-sectional dimensions at the proximal end of the support member to the cross-sectional dimensions at the distal end of the support element.

[0290] 89. A tool assembly according to any item described herein, wherein the draft angle of the corresponding forming element in the plurality of forming elements allows an acoustic core formed using the tool assembly to exhibit good release from the corresponding forming tool in the plurality of forming tools.

[0291] 90. The tool assembly of any clause herein, wherein the draft angle is provided by one or more dimensions of the resonant unit of the acoustic core configured to be formed by the tool assembly.

[0292] 91. A tool assembly according to any item described herein, wherein at least some of the resonant units of the acoustic core have a convergence angle corresponding to the draft angle of the corresponding forming element, and / or wherein at least some of the resonant units of the acoustic core have a convergence angle different from the draft angle of the corresponding forming element.

[0293] 92. The tool assembly of any clause herein, wherein the draft angle is about 0.5 degrees to about 10 degrees.

[0294] 93. A tool assembly according to any item herein, wherein the tool assembly comprises an injection molding assembly, or wherein the tool assembly comprises a compression molding assembly, or wherein the tool assembly comprises a press forming assembly.

[0295] 94. A tool assembly according to any clause herein, wherein the tool assembly is configured to form an acoustic core having a curved profile.

[0296] 95. A tool assembly according to any clause herein, wherein the plurality of forming tools include one or more gate elements through which moldable material can be injected into the mold cavity.

[0297] 96. A tool assembly according to any item described herein, wherein the multiple forming tools respectively include one or more ejector pins, and the one or more ejector pins are respectively capable of extending through the corresponding support members and / or through the corresponding forming elements, and the one or more ejector pins are configured to push the acoustic core formed using the tool assembly away from the corresponding forming tool and / or out of the mold cavity.

[0298] 97. A tool assembly according to any item described herein, wherein at least one of the one or more ejector pins pushes against a support element of a corresponding mating forming tool among the multiple forming tools when actuated; and / or wherein at least one of the one or more ejector pins pushes against a partition member of a partitioned resonance unit formed by the tool assembly when actuated.

[0299] 98. A tool assembly according to any item described herein, wherein at least one of the multiple forming tools includes one or more forming elements, and the one or more forming elements have protrusions extending from the main body portion of the corresponding forming element, and the protrusions are configured to form partitioned orifices in partitioned parts of the partitioned resonant unit formed by the tool assembly, and when the acoustic core is formed, the protrusions approach and / or contact the corresponding matching forming tool.

[0300] 99. A tool assembly according to any clause herein, wherein the tool assembly is constructed to form an acoustic core as described in any clause herein.

[0301] 100. An acoustic core construction system, wherein the acoustic core construction system is configured to determine the construction of an acoustic core as described in any of the clauses herein, such as according to the method as described in any of the clauses herein.

[0302] 101. A tool assembly configuration system, wherein the tool assembly configuration system is configured to determine the configuration of a tool assembly as described in any of the clauses herein, for example according to the method as described in any of the clauses herein.

[0303] 102. A computer-readable medium comprising computer-executable instructions, which, when executed by a processor, cause the processor to perform a method, the method comprising: determining a configuration of an acoustic core comprising an array of resonance units, wherein determining the configuration of the acoustic core comprises: determining a configuration of a plurality of coupled resonance units, respective coupled resonance units of the plurality of coupled resonance units defining a preceding resonance space and a succeeding resonance space, and comprising at least one unit wall having one or more wall openings, the one or more wall openings defining a passage between the preceding resonance space and the succeeding resonance space; and determining a configuration of a plurality of high-frequency resonance units respectively defining high-frequency resonance spaces, respective high-frequency resonance units of the plurality of high-frequency resonance units matching respective coupled resonance units of the plurality of coupled resonance units.

[0304] 103. A computer-readable medium comprising computer-executable instructions, which, when executed by a processor, cause the processor to perform a method comprising: determining a configuration of a tool assembly and / or a configuration of one or more forming tools used in the tool assembly using a tool assembly construction system; making the one or more forming tools and / or assembling a tool assembly including the one or more forming tools; and forming the acoustic core using the tool assembly including the one or more forming tools; wherein the tool assembly and / or the one or more forming tools have a configuration determined at least in part based on a configuration determined for the acoustic core; wherein the acoustic core comprises: an array of resonant units, the resonant units The element array includes a plurality of resonance unit groups, a corresponding resonance unit group in the resonance unit groups includes a plurality of resonance units, at least some of the plurality of resonance units include: partitioned resonance units, the partitioned resonance units include convergent resonance units and divergent resonance units, the convergent resonance units and the divergent resonance units are defined by a plurality of unit walls formed integrally with each other and partition members formed integrally with the plurality of unit walls, the partition members at least partially define the convergent resonance units and the divergent resonance units; wherein the convergent resonance units define an upper resonance space defined by the partition members and a top surface of the resonance unit array, and wherein the divergent resonance units define a lower resonance space defined by the partition members and a bottom surface of the resonance unit array.

[0305] 104. A computer-readable medium according to any of the clauses herein, wherein the computer-readable medium comprises computer-executable instructions which, when executed by a processor, cause the processor to perform the method described in any of the clauses herein.

[0306] This written description uses exemplary embodiments to describe the subject matter of the present disclosure, including the best mode, and also enables any person skilled in the art to practice such subject matter, including making and using any device or system and performing any combined method. The patentable scope of the subject matter of the present disclosure is defined by the claims, and may include other examples that occur to one skilled in the art. Such other examples are intended to fall within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims.

Claims

1. An acoustic core, characterized in that: include: A resonance unit array, the resonance unit array comprising a plurality of resonance unit groups, a corresponding resonance unit group in the plurality of resonance unit groups comprising a plurality of resonance units, at least some of the plurality of resonance units comprising: A partitioned resonance unit, the partitioned resonance unit comprising a first convergent resonance unit and a first divergent resonance unit, the first convergent resonance unit and the first divergent resonance unit being defined by a plurality of unit walls formed integrally with each other and a partitioning member formed integrally with the plurality of unit walls, the partitioning member at least partially defining the first convergent resonance unit and the first divergent resonance unit; wherein the first converging resonance unit defines an upper resonance space defined by the partition element and a top surface of the resonance unit array, and wherein the first diverging resonance unit defines a lower resonance space defined by the partition element and a bottom surface of the resonance unit array; wherein at least some of the plurality of resonance units include: a coupling resonance unit, the coupling resonance unit defining a coupling resonance space, the coupling resonance space including a preceding resonance space and a subsequent resonance space, and the coupling resonance unit including at least one unit wall having one or more wall apertures defining a passage between the preceding resonance space and the subsequent resonance space; and wherein the coupling resonance unit is configured as a second divergent resonance unit, and the coupling resonance unit is located at a portion of the acoustic core having a concave curve profile; or The coupling resonance unit is configured as a second converging resonance unit, and the coupling resonance unit is located at a portion of the acoustic core having a convex curve profile.

2. The acoustic core according to claim 1, characterized in that: wherein at least some of the plurality of resonance units include: A third divergent resonance unit, wherein the third divergent resonance unit is defined by the top surface and the bottom surface; and / or A third converging resonance unit is defined by the top surface and the bottom surface.

3. The acoustic core according to claim 1, characterized in that: The curved contour is defined by the top surface and / or the bottom surface.

4. The acoustic core according to claim 3, characterized in that: The curved profile comprises a convex curved profile and / or a concave curved profile.

5. The acoustic core according to claim 4, characterized in that wherein the resonance unit array comprises a plurality of third divergent resonance units defined by the top surface and the bottom surface at positions where the acoustic core has a convex curved profile; and / or wherein, The resonance unit array includes a plurality of third converging resonance units defined by the top surface and the bottom surface at locations where the acoustic core has a concave curved profile.

6. The acoustic core according to claim 1, characterized in that The first convergent resonance unit is constructed as a high-frequency resonance unit defining a high-frequency resonance space, and the high-frequency resonance unit is matched with the coupling resonance unit.

7. The acoustic core according to claim 6, characterized in that wherein at least some of the plurality of resonance units include: a first intermediate frequency resonance unit, the first intermediate frequency resonance unit defining an intermediate frequency resonance space, the intermediate frequency resonance space being bounded by the top surface and an additional partitioning member, the additional partitioning member separating the intermediate frequency resonance space from the coupling resonance space; and The first intermediate frequency resonance unit is constructed as a convergent resonance unit.

8. The acoustic core according to claim 1, characterized in that The first converging resonance unit presents a convergence angle from 0.5 to 30 degrees relative to the longitudinal axis of the first converging resonance unit; and / or the first diverging resonance unit presents a convergence angle from -0.5 to -30 degrees relative to the longitudinal axis of the first diverging resonance unit.

9. The acoustic core according to claim 1, characterized in that Wherein the acoustic core comprises an injection molded acoustic core, or wherein the acoustic core comprises a press-formed acoustic core, or wherein the acoustic core comprises an additively manufactured acoustic core.

10. The acoustic core according to claim 1, characterized in that Wherein the first convergent resonance unit is at least partially realized by the cross-sectional thickness of one or more cell walls and / or at least partially by the angle or orientation of one or more cell walls; and / or wherein the first divergent resonance unit is at least partially realized by the cross-sectional thickness of one or more cell walls and / or at least partially by the angle or orientation of one or more cell walls.

11. A tool assembly for forming an acoustic core, characterized in that The tool kit includes: a plurality of forming tools, respective forming tools of the plurality of forming tools comprising a support member and a plurality of forming elements coupled to the support member; wherein a mold cavity defined at least in part by the plurality of forming elements corresponds to an acoustic core to be formed by the tool assembly when the plurality of forming tools are operated in proximity to one another; The acoustic core comprises: A resonance unit array, the resonance unit array comprising a plurality of resonance unit groups, a corresponding resonance unit group in the plurality of resonance unit groups comprising a plurality of resonance units, at least some of the plurality of resonance units comprising: A partitioned resonance unit, the partitioned resonance unit comprising a first convergent resonance unit and a first divergent resonance unit, the first convergent resonance unit and the first divergent resonance unit being defined by a plurality of unit walls formed integrally with each other and a partitioning member formed integrally with the plurality of unit walls, the partitioning member at least partially defining the first convergent resonance unit and the first divergent resonance unit; wherein the first converging resonance unit defines an upper resonance space defined by the partition element and a top surface of the resonance unit array, and wherein the first diverging resonance unit defines a lower resonance space defined by the partition element and a bottom surface of the resonance unit array; wherein at least some of the plurality of resonance units include: a coupling resonance unit, the coupling resonance unit defining a coupling resonance space, the coupling resonance space including a preceding resonance space and a subsequent resonance space, and the coupling resonance unit including at least one unit wall having one or more wall apertures defining a passage between the preceding resonance space and the subsequent resonance space; and wherein the coupling resonance unit is configured as a second divergent resonance unit, and the coupling resonance unit is located at a portion of the acoustic core having a concave curve profile; or The coupling resonance unit is configured as a second converging resonance unit, and the coupling resonance unit is located at a portion of the acoustic core having a convex curve profile.

12. The tool assembly according to claim 11, characterized in that The plurality of forming elements have draft angles such that a cross-sectional dimension of the corresponding forming element decreases from a cross-sectional dimension at a proximal end of the support member to a cross-sectional dimension at a distal end of the support member.

13. The tool assembly according to claim 12, characterized in that Wherein the draft angle of a corresponding forming element of the plurality of forming elements allows an acoustic core formed using the tool assembly to exhibit good release from a corresponding forming tool of the plurality of forming tools.

14. The tool assembly according to claim 12, characterized in that Wherein the draft angle is provided by one or more dimensions of the plurality of resonant units of the acoustic core configured to be formed by the tool assembly.

15. The tool assembly according to claim 12, characterized in that wherein at least some of the plurality of resonant units of the acoustic core have a convergence angle corresponding to the draft angle of the corresponding forming element, and / or wherein at least some of the plurality of resonant units of the acoustic core have a convergence angle different from the draft angle of the corresponding forming element.

16. The tool assembly according to claim 12, characterized in that Wherein the draft angle is about 0.5 degrees to about 10 degrees.

17. The tool assembly according to claim 11, characterized in that Wherein the tool assembly comprises an injection molding assembly, or wherein the tool assembly comprises a compression molding assembly, or wherein the tool assembly comprises a press-forming assembly.

18. The tool assembly according to claim 11, characterized in that The tool assembly is configured to form an acoustic core having a curved profile.

19. A method of forming an acoustic core, characterized in that The method comprises: determining, using a tool assembly configuration system, a configuration of a tool assembly and / or a configuration of one or more forming tools for use in the tool assembly; making the one or more forming tools and / or assembling a tool assembly including the one or more forming tools; and forming the acoustic core using the tool assembly including the one or more forming tools; wherein the tool assembly and / or the one or more forming tools have a configuration determined at least in part based on a configuration determined for the acoustic core; The acoustic core comprises: A resonance unit array, the resonance unit array comprising a plurality of resonance unit groups, a corresponding resonance unit group in the plurality of resonance unit groups comprising a plurality of resonance units, at least some of the plurality of resonance units comprising: A partitioned resonance unit, the partitioned resonance unit comprising a first convergent resonance unit and a first divergent resonance unit, the first convergent resonance unit and the first divergent resonance unit being defined by a plurality of unit walls formed integrally with each other and a partitioning member formed integrally with the plurality of unit walls, the partitioning member at least partially defining the first convergent resonance unit and the first divergent resonance unit; wherein the first converging resonance unit defines an upper resonance space defined by the partition element and a top surface of the resonance unit array, and wherein the first diverging resonance unit defines a lower resonance space defined by the partition element and a bottom surface of the resonance unit array; wherein at least some of the plurality of resonance units include: a coupling resonance unit, the coupling resonance unit defining a coupling resonance space, the coupling resonance space including a preceding resonance space and a subsequent resonance space, and the coupling resonance unit including at least one unit wall having one or more wall apertures defining a passage between the preceding resonance space and the subsequent resonance space; and wherein the coupling resonance unit is configured as a second divergent resonance unit, and the coupling resonance unit is located at a portion of the acoustic core having a concave curve profile; or The coupling resonance unit is configured as a second converging resonance unit, and the coupling resonance unit is located at a portion of the acoustic core having a convex curve profile.

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