Stator blade with acoustic lining

Abstract

The present disclosure relates to a stator blade with an acoustic liner, comprising: a first surface wherein the first surface comprises a first portion with a through hole; a second surface opposite the first surface, wherein the first surface and the second surface are separated by a blade thickness; the cavity layer is located between the first part and the second surface, and the cavity layer comprises a plurality of cavities; wherein each of the plurality of cavities is filled with particulate matter, and wherein the filling rate of each cavity is different to obtain the desired optimal acoustic impedance.

Description

Technical Field

[0001] The present disclosure relates to the field of aircraft engines, and in particular to a stator blade with an acoustic liner. Background Art

[0002] As the bypass ratio of aircraft engines (such as civil aviation turbofan engines) gradually increases, the contribution of fans / compressors to noise becomes more and more significant, becoming one of the main noise sources of aircraft. Acoustic lining has become the main means to reduce fan / compressor noise.

[0003] However, the shortening of the nacelle of the future turbofan engine reduces the layout area of ​​the inlet duct acoustic lining, which limits the size of the acoustic lining, thereby limiting the noise reduction effect of the acoustic lining. In addition, the noise absorption band of the traditional single-degree-of-freedom acoustic lining is narrow, and although the multi-degree-of-freedom acoustic lining can broaden the sound absorption band, it also has the problems of complex processing technology, large size, and more structural weight increase.

[0004] The present disclosure has been improved with respect to but not limited to the above-mentioned factors. Summary of the invention

[0005] To this end, the present disclosure proposes a stator blade / support plate with a sound lining that can be arranged at a fan casing, between a fan and an outer duct stator, at a diverter ring, and the like. The stator blade / support plate of the present disclosure is a structure that transforms an engine stator blade (including a fan boost stage outer duct outlet blade, a boost stage inner duct stator blade, and a turbine stator blade) or a support plate into a cavity (i.e., a Helmholtz resonance cavity) or other structure with a sound absorption function. The stator blade / support plate of the present disclosure is also filled with particles with a sound dissipation effect in the cavity. As a result, the stator blade / support plate of the present disclosure has a new blade structure with a sound lining. This structure utilizes particles with a sound dissipation effect filled in the cavity of the sound lining to improve the broadband sound absorption effect of the blade. At the same time, a metal wire mesh is used to seal the particles to prevent leakage. In addition, by using different types of particles and different proportions of the volume of the cavities they occupy, the acoustic reactance and acoustic resistance of different acoustic cavities can be adjusted to achieve the design of non-uniform acoustic lining, further improving the broadband sound absorption of blades with acoustic lining. This configuration achieves the purpose of reducing the broadband noise of aircraft engines while ensuring the economy and power of aircraft engines, without increasing the thickness and weight of stator blades.

[0006] According to a first aspect of the present disclosure, there is provided a stator blade with an acoustic liner, comprising: a first surface, wherein the first surface comprises a first portion with a through hole; a second surface opposite to the first surface, wherein the first surface and the second surface are separated by the thickness of the blade; and a cavity layer located between the first portion and the second surface, wherein the cavity layer comprises a plurality of cavities; wherein each of the plurality of cavities is filled with particulate matter, and wherein the filling rate of each cavity is different to obtain the desired optimal acoustic impedance.

[0007] According to an embodiment, a metal mesh is further arranged in each cavity to separate the particles from the first portion.

[0008] According to another embodiment, the plurality of cavities are honeycomb-shaped, and the particles filled in each cavity are different in material and / or size.

[0009] According to yet another embodiment, when two or more kinds of particles are filled in each cavity, the particles are separated by a metal mesh.

[0010] According to yet another embodiment, the inner diameter of the cavity is between 1-10 cm, the diameter of the particles is between 0.1-10 mm, and the aperture of the wire mesh is smaller than the smallest diameter of the particles.

[0011] According to yet another embodiment, the porosity of the granules is greater than 10%, and the perforation rate of the first portion is between 5% and 30%.

[0012] According to yet another embodiment, the through hole is a circle or a regular polygon, a maximum width of the through hole in a plane defined by the first portion is no greater than 2 mm, and a thickness of the first portion is no greater than 2 mm.

[0013] According to yet another embodiment, the diameters of the inscribed circles of each cavity are different in size.

[0014] According to yet another embodiment, the first portion occupies 20%-40% of the surface area of ​​the first surface, and the cavity layer occupies 50%-70% of the thickness of the blade.

[0015] According to a second aspect of the present disclosure, an aircraft is provided, comprising the stator blade according to the first aspect of the present disclosure.

[0016] According to an embodiment, the stator blades are arranged as at least one of the following structures of the aircraft: fan duct outlet blades, duct support plates, boost stage stator blades, high pressure compressor stator blades, turbine stator blades.

[0017] According to a third aspect of the present disclosure, a method for manufacturing a stator blade according to the first aspect of the present disclosure is provided, comprising: collecting sound field data; obtaining required acoustic impedance based on the sound field data; and filling the cavity with suitable particulate matter according to the acoustic impedance.

[0018] Aspects generally include methods, apparatus, systems, computer program products, and processing systems substantially as described herein with reference to and as illustrated by the accompanying figures.

[0019] The foregoing has broadly outlined the features and technical advantages of examples according to the present disclosure so that the following detailed description can be better understood. Additional features and advantages will be described hereinafter. The disclosed concepts and specific examples can be easily used as the basis for modifying or designing other structures for implementing the same purpose as the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein, both in terms of their organization and method of operation, and the associated advantages will be better understood by considering the following description in conjunction with the accompanying drawings. Each of the accompanying drawings is provided for illustration and description purposes and does not define limitations on the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to understand in detail the manner in which the above-stated features of the present disclosure are used, the above briefly summarized content may be described in more detail with reference to various aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only certain typical aspects of the present disclosure and should not be considered to limit its scope, as the description may allow for other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0021] Figure 1 is a schematic cross-sectional view of a stator blade with an acoustic liner according to an exemplary embodiment of the present disclosure;

[0022] Figure 2 is a schematic cross-sectional view of a cavity of a stator blade filled with particulate matter according to an exemplary embodiment of the present disclosure;

[0023] Figure 3 is a schematic cross-sectional view of a cavity of a stator blade filled with various particulates according to an exemplary embodiment of the present disclosure;

[0024] Figure 4 is another schematic cross-sectional view of a cavity of a stator blade filled with a plurality of particulates according to an exemplary embodiment of the present disclosure;

[0025] Figure 5 is a schematic diagram of an aircraft according to an example embodiment of the present disclosure; and

[0026] Figure 6A flow chart of a method for manufacturing a stator blade according to an example embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0027] Terminology explanation:

[0028] Acoustic lining: A sound-absorbing structure consisting mainly of a perforated plate, a cavity layer and a backing plate, usually laid on the wall;

[0029] Broadband noise: noise that exists widely over a fairly wide frequency range;

[0030] Single-tone noise: noise distributed only at the frequency at which the fan blades pass;

[0031] Blade passing frequency: the frequency at which a blade of the fan rotates to the position of the adjacent blade;

[0032] Stator blades: stationary blades that guide the flow in the booster stage and turbine;

[0033] Support plate: the supporting structure connecting the intermediate casing and the nacelle;

[0034] Bypass ratio: the ratio of the mass flow rate of the outer bypass of a turbofan engine to the mass flow rate of the inner bypass;

[0035] Nacelle: The nacelle system of an engine generally consists of the engine air intake, fairing, internal fixtures, thrust reverser, and exhaust system (tail nozzle), etc. The engine nacelle wraps the engine body inside, providing an installation platform and necessary protection for the engine body.

[0036] The inventors realize that the bypass ratio of civil aviation turbofan engines is gradually increasing, and the contribution of fan / compressor noise is becoming more and more significant. Acoustic lining is the main means to reduce fan / compressor noise. However, the shortening of the nacelle of future turbofan engines reduces the layout area of ​​the inlet acoustic lining. Therefore, more noise reduction means are needed to reduce aircraft engine noise.

[0037] The inventors also realized that the sound lining of the prior art generally has good sound absorption performance for the single-tone noise of aircraft engines, but poor sound absorption performance for broadband noise. However, for aircraft engines, broadband noise is an important component of noise. However, if the stator blades / support plates are transformed into a multi-degree-of-freedom sound lining structure, that is, composed of a plurality of the above-mentioned structures stacked together, then this structure can have a better broadband sound absorption effect. However, the increased thickness and weight of the stator blades not only affect the aerodynamic performance of the engine, but also increase the weight of the engine, which is not economically effective. Therefore, there is a sharp contradiction between engine noise reduction and ensuring the power and economy of the engine.

[0038] To this end, the present disclosure proposes to arrange stator blades / support plates with sound lining at positions such as the fan casing, between the fan and the outer duct stator, and at the diverter ring. The stator blades / support plates disclosed in the present disclosure are structures such as engine stator blades (including fan boost stage outer duct outlet blades, boost stage inner duct stator blades, and turbine stator blades) or support plates that are transformed into cavities (i.e., Helmholtz resonance cavities) or other structures with sound absorption functions. The stator blades / support plates disclosed in the present disclosure are also filled with particles with sound dissipation effects in the cavities. Therefore, the stator blades / support plates disclosed in the present disclosure have a new type of blade structure with sound lining. The structure utilizes particles with sound dissipation effects filled in the cavity of the sound lining to improve the broadband sound absorption effect of the blade. At the same time, the particles are sealed with a metal mesh to prevent leakage. In addition, the acoustic reactance and acoustic resistance of different sound cavities can be adjusted by different types of particles and different volume proportions of the cavities occupied, so as to achieve the design of non-uniform sound lining and further improve the broadband sound absorption of the blade with sound lining. This configuration achieves the purpose of reducing the broadband noise of the aircraft engine while ensuring the economy and power of the aircraft engine without increasing the thickness and weight of the stator blades.

[0039] The stator blades / support plates disclosed in the present invention can be used in structures such as aircraft engine stators (including fan boost stage outer duct outlet blades, boost stage inner duct stator blades, turbine stator blades, etc.) or outer duct support plates.

[0040] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. This detailed description includes specific details to provide a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details.

[0041] Reference below Figure 1 , which shows a schematic cross-sectional view of a stator blade 100 with an acoustic liner according to an exemplary embodiment of the present disclosure.

[0042] like Figure 1 As shown, the stator blade 100 may include a first surface 8 and a second surface 7 opposite the first surface 8, wherein the first surface 8 and the second surface 7 are separated by a blade thickness. As can be seen, the blade thickness of the stator blade 100 may be non-uniform. In another embodiment, the blade thickness of the stator blade 100 may be uniform.

[0043] Those skilled in the art will appreciate that although Figure 1 The cross-sections of the first surface 8 and the second surface 7 of the stator blade 100 are shown as arc-shaped, and the stator blade 100 may have any suitable shape, which depends on the installation position of the stator blade 100, and will not be described in detail here.

[0044] like Figure 1 As shown, the first surface 8 may include a first portion 1 with through holes. In one embodiment of the present disclosure, the first portion 1 may occupy any suitable proportion of the surface area of ​​the first surface 8. In one embodiment of the present disclosure, the entire first surface 8 may be composed of a perforated plate or other porous material with sound dissipation effect, so that the first portion 1 may occupy the entire first surface 8. In a preferred embodiment, the first portion 1 may occupy 20%-40% of the surface area of ​​the first surface 8. Preferably, as Figure 1 As shown, the first portion 1 may be located at the “middle” of the first surface 8 . In yet another embodiment of the present disclosure, the first portion 1 may be located at the “thickest” portion of the stator blade 100 .

[0045] According to an embodiment of the present disclosure, the perforation rate, shape of the through holes, spacing between the through holes, and arrangement of the through holes of the first part 1 can be arbitrary. Preferably, the perforation rate of the first part is between 5% and 30%, and the through holes in the first part 1 are circular or regular polygonal. In this embodiment, the thickness of the first part 1 can be adjusted according to the actual working conditions, but limited to the structural requirements of the stator blade 100, the thickness of the first part 1 is not greater than 2 mm. It is also preferred that the maximum width of the through hole in the plane defined by the first part 1 is not greater than 2 mm.

[0046] As from Figure 1 As seen in FIG. 1 , the stator blade 100 may further include a cavity layer 2 located between the first portion 1 and the second surface 7. The cavity layer 2 may include a plurality of cavities, such as Figure 1 As shown in the oblique line shaded portion in . It will be understood that the cavity layer 2 can occupy any suitable proportion of the blade thickness of the stator blade. In one embodiment of the present disclosure, the cavity layer 2 can occupy 50%-70% of the blade thickness of the stator blade to take into account both the sound absorption effect and the structural strength requirements of the stator blade.

[0047] In one embodiment of the present disclosure, the cross-sectional shape of the cavity in the cavity layer 2 can be arbitrary. Typically, the cavity can be a honeycomb-shaped cavity. In another embodiment of the present disclosure, the diameters of the inscribed circles of the various cavities can be different, and the diameters of the inscribed circles of the cavities can be adjusted according to the working conditions according to the different positions of the stator blades 100. Preferably, the inner diameter of the cavity is between 1-10 cm.

[0048] from Figure 1 It can also be seen that the stator blade 100 also includes a "concave surface" 3 in contact with the cavity layer 2. Thus, the concave surface 3, the cavity layer 2, and the first part 1 can constitute an acoustic liner for sound absorption, and the concave surface 3 can be referred to as the backing layer of the acoustic liner.

[0049] will understand, although Figure 1In the figure, the first part 1 and the cavity layer 2 are shown as being integrally formed with the stator blade 100. The first part 1, the cavity layer 2, and the backing layer 3 can also be separated from the stator blade 100. In this embodiment, the first part 1, the cavity layer 2, and the backing layer 3 can constitute an independent acoustic liner and be embedded in the "groove" in the stator blade 100. According to this embodiment, the acoustic liner and the groove of the stator blade 100 can have matching fastening structures (such as a snap-fit ​​structure) so that the acoustic liner can be firmly embedded in the stator blade 100.

[0050] like Figure 1 As shown, the stator blade 100 may also include a blade body 4, a leading edge 5, a trailing edge 6, etc., which are not described in detail. Preferably, the first surface 8 and the second surface 7 may be designed to smooth the airflow, and the blade body 4 may be designed to have a guiding effect on the airflow.

[0051] In a preferred embodiment of the present disclosure, the cavity in the cavity layer 2 may be filled with particles 9, such as Figure 2 To prevent particles from clogging the perforated first part 1 and leaking from the first part 1, a wire mesh is arranged in each cavity to separate the particles from the first part 1. Figure 2 As shown, a layer of wire mesh 10 is also covered on the granules 9, wherein the aperture of the wire mesh 10 is smaller than the diameter of the granules 9. Preferably, the diameter of the granules 9 is between 0.1-10 mm, and the aperture of the wire mesh 10 is smaller than the minimum diameter of the granules 9. Preferably, the material of the granules 9 can be any suitable material with sound dissipation effect, such as cork (also known as cork, cork, cork bark), balsa wood (also known as balsa wood, balsa wood), bird fluff, etc. Therefore, when the sound wave enters the cavity, in addition to the sound dissipation occurring at the perforated first part 1, it rubs against the granules 9 at a smaller scale level, thereby achieving a broadband sound absorption effect.

[0052] The inventors have discovered that the volume of the cavity occupied by the particulate matter 9 will affect the acoustic impedance of the acoustic liner, and the pressure pulsations at different locations on the blade surface are different, and the optimal acoustic impedance required for noise reduction is also different. Therefore, in a preferred embodiment of the present disclosure, in order to obtain the desired optimal acoustic impedance, the particulate matter 9 can occupy different volume proportions of the cavity according to actual needs, that is, the filling rate of each cavity is different. As a result, the acoustic impedance at the surface of the stator blade 100 (for example, the first part 1 of the first surface 8) can be adjusted as needed (through different filling rates of the cavities of the cavity layer 2), so that the cavities at different locations can achieve the optimal noise reduction effect. Figure 2 , which shows different filling rates of the three cavities.

[0053] Preferably, the particles 9 filled in each cavity may be different in material and / or size to obtain the desired broadband noise reduction effect. Preferably, in order to have the sound absorption effect of different particles, multiple layers of different particles 9 may be arranged in the cavity, such as Figure 3 As shown. Figure 3 In the embodiment, different particles are separated by metal mesh 10. In addition, in order to reduce the impact on acoustic impedance while achieving the sound absorption effect of different particles, two or more different particles can be directly mixed in the cavity, such as Figure 4 shown.

[0054] In a preferred embodiment of the present disclosure, in order to obtain a better sound absorption effect, the porosity of the particles 9 may be greater than 10%.

[0055] refer to Figure 5 , which shows a schematic diagram of an aircraft 500 according to an exemplary embodiment of the present disclosure. In one embodiment, the aircraft 500 may include a stator blade according to the above embodiment of the present disclosure, such as a combination of Figure 1 The stator blade 100.

[0056] In a preferred embodiment of the present disclosure, the stator blades 100 may be arranged into any suitable structure of the aircraft 500, such as fan duct outlet blades, duct support plates, boost stage stator blades, high pressure compressor stator blades, turbine stator blades, and the like.

[0057] refer to Figure 6 , which shows a flow chart of a method 600 for manufacturing a stator blade according to an example embodiment of the present disclosure.

[0058] like Figure 6 As shown, method 600 may include collecting acoustic field data at block 610. In one embodiment of the present disclosure, the acoustic field data is associated with a stator blade (such as a combination of Figure 1 The installation position of the stator blade 100) corresponds to the above. It will be appreciated that any suitable device may be used to collect the sound field data, such as a microphone, a sound sensor, etc. According to this embodiment, the sound field data may include a frequency range, an intensity range, etc. of the sound wave.

[0059] Thereafter, at block 620, the method 600 may include obtaining a required acoustic reactance based on the sound field data. For example, after acquiring the sound field data, the method 600 may calculate the required acoustic reactance based on the frequency range and corresponding intensity of the sound waves at the location to absorb the sound waves. It will be appreciated that the method 600 may calculate the required acoustic reactance in real time based on the sound field data or may find the required acoustic reactance through a pre-calculated lookup table.

[0060] Finally, at block 630, method 600 may include filling the cavity with particles according to the acoustic impedance. For example, the acoustic impedance may be stored in a lookup table in association with the corresponding cavity filling rate, particle type, etc. Thus, after obtaining the required acoustic impedance, the lookup table may be used to find out which particle type and filling rate the cavity at the corresponding position should be filled with. Subsequently, the cavity may be filled accordingly.

[0061] It will be appreciated that the terms "stator," "stator blade," "blade," "strut," etc., are used interchangeably in this disclosure.

[0062] The above detailed description includes references to the accompanying drawings, which form part of the detailed description. The accompanying drawings illustrate specific embodiments that can be practiced by way of illustration. These embodiments are also referred to herein as "examples". Such examples may include elements other than those shown or described. However, examples including the elements shown or described are also contemplated. In addition, examples using any combination or arrangement of those elements shown or described are also contemplated, or with reference to the specific examples (or one or more aspects thereof) shown or described herein, or with reference to other examples (or one or more aspects thereof) shown or described herein.

[0063] In the appended claims, the terms "including" and "comprising" are open ended, that is, systems, devices, articles, or processes having elements other than those elements listed after such terms in a claim are still deemed to fall within the scope of that claim. Furthermore, in the appended claims, the terms "first," "second," and "third," etc. are used merely as labels and are not intended to indicate a numerical order to their objects.

[0064] In addition, the order of each operation explained in this specification is exemplary. In alternative embodiments, each operation can be performed in a different order than that shown in the drawings, and each operation can be combined into a single operation or split into more operations.

[0065] The above description is intended to be illustrative, not restrictive. For example, the examples described above (or one or more aspects thereof) may be used in conjunction with other embodiments. Other embodiments may be used, such as by a person of ordinary skill in the art, after reviewing the above description. The abstract allows the reader to quickly determine the nature of the present technology disclosure. The abstract is submitted, and it is understood that the abstract will not be used to interpret or limit the scope or meaning of the claims. In addition, in the above specific embodiments, various features may be grouped together to make the disclosure fluent. However, the claims may not state every feature disclosed herein, because the embodiments may characterize a subset of the features. In addition, the embodiments may include fewer features than those disclosed in a particular example. Therefore, the attached claims are thus incorporated into the specific embodiments, and a claim exists independently as a separate embodiment. The scope of the embodiments disclosed herein should be determined with reference to the attached claims and the full scope of equivalents to which such claims are entitled.

Claims

1. A stator blade with an acoustic liner, include: a first surface, wherein the first surface includes a first portion having a through hole; a second surface opposite the first surface, wherein the first surface and the second surface are separated by a blade thickness; as well as a cavity layer located between the first portion and the second surface, the cavity layer comprising a plurality of cavities; Each of the plurality of cavities is filled with particles, and the filling rate of each cavity is different to obtain the desired optimal acoustic impedance.

2. The stator blade according to claim 1, It is characterized in that A wire mesh is also arranged in each cavity to separate the particles from the first portion.

3. The stator blade according to claim 2, It is characterized in that The plurality of cavities are honeycomb-shaped, and the particles filled in each cavity are different in material and / or size.

4. The stator blade according to claim 2, It is characterized in that When two or more particles are filled in each cavity, the particles are separated by a metal mesh.

5. The stator blade according to claim 2, It is characterized in that The inner diameter of the cavity is between 1-10 cm, the diameter of the particles is between 0.1-10 mm, and the aperture of the metal mesh is smaller than the minimum diameter of the particles.

6. The stator blade according to claim 1, It is characterized in that The porosity of the particles is greater than 10%, and the perforation rate of the first part is between 5% and 30%.

7. The stator blade according to claim 1, It is characterized in that The through hole is circular or regular polygonal, and its maximum width in the plane defined by the first part is no greater than 2 mm, and the thickness of the first part is no greater than 2 mm.

8. The stator blade according to claim 1, It is characterized in that The diameters of the inscribed circles of each cavity are different.

9. The stator blade according to claim 1, It is characterized in that The first portion occupies 20%-40% of the surface area of ​​the first surface, and the cavity layer occupies 50%-70% of the thickness of the blade.

10. An aircraft comprising a stator blade according to any one of claims 1-9.

11. The aircraft according to claim 10, It is characterized in that The stator blades are arranged into at least one of the following structures of the aircraft: fan duct outlet blades, duct support plates, booster stage stator blades, high pressure compressor stator blades, and turbine stator blades.

12. A method for manufacturing a stator blade according to any one of claims 1 to 9, include: Collect sound field data; Obtaining required acoustic reactance based on sound field data; as well as The cavity is filled with suitable particles depending on the acoustic reactance.

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