Propulsion flow path duct system and method

Abstract

This invention relates to a propulsion flow path system and method. The flow path system includes a base defining a flow surface. The base has an inner surface and an outer surface. A plurality of perforations are formed through the base between the inner and outer surfaces. A plurality of support members define a plurality of chambers. The plurality of support members extend outward from the outer surface of the base. One or more of the plurality of chambers are in fluid communication with one or more of the plurality of perforations. A backing surface is fixed to the plurality of support members. The plurality of support members are disposed between the base and the backing surface. The one or more of the plurality of chambers are in fluid communication with an internal volume defined by the inner surface of the base through the one or more of the plurality of perforations. The base, the plurality of support members, and the backing surface can be integrally formed as a monolithic load-bearing structure.

Description

[0001] Cross-reference to related applications

[0002] This application relates to and claims priority to U.S. Provisional Application No. 63 / 074,658, filed September 4, 2020, entitled “Integrated Propulsion FlowPath System and Method for Reduced Noise,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments of this disclosure relate to acoustic damping systems and methods, such as additively manufactured monolithic acoustic damping systems and methods within propulsion flow paths of aircraft. Background Technology

[0004] Various aircraft include propulsion systems that generate noise. For example, in commercial aircraft, engine nacelle air intakes include fan blades and other noise-generating components. To reduce the noise generated, acoustic linings have been installed in such areas to dampen sound. Known linings, for example, include porous or mesh panels covering air chambers with a rigid backing, typically made of titanium, stainless steel, or aluminum. In some applications, the air chambers form a honeycomb structure to provide some stiffness to the lining. Some applications may include two air chambers separated by a mesh material. Typically, the lining acts as a noise damping and phase-cancelling mechanism.

[0005] However, the known linings are usually installed on the main structure and increase the complexity of the overall design. Summary of the Invention

[0006] There is a need for a system and method that efficiently and effectively reduces noise associated with various components within the propulsion system of an aircraft. Furthermore, for example, there is a need for a less complex system and method for reducing noise related to aircraft engines.

[0007] In view of these needs, certain embodiments of this disclosure provide a flow path duct system for a propulsion system of an aircraft. The flow path duct system includes a base defining a flow surface. The base has an inner surface and an outer surface. A plurality of perforations are formed through the base between the inner and outer surfaces. A plurality of support members define a plurality of chambers. The plurality of support members extend outwardly from the outer surface of the base. One or more of the plurality of chambers are in fluid communication with one or more of the plurality of perforations. A backing surface is secured to the plurality of support members. The plurality of support members are disposed between the base and the backing surface. The one or more of the plurality of chambers are in fluid communication with the internal volume defined by the inner surface of the base through the one or more of the plurality of perforations.

[0008] In at least one embodiment, the base, the plurality of support members, and the backing surface are integrally formed into a single load-bearing structure. For example, the base, the plurality of support members, and the backing surface are additively manufactured together.

[0009] In at least one embodiment, each of the plurality of chambers is in fluid communication with at least one of the plurality of perforations. As another example, the plurality of chambers and the plurality of perforations cooperate to provide a plurality of Helmholtz resonators.

[0010] In at least one embodiment, the plurality of chambers are shaped as one or more of triangles, rhombuses, circles, and hexagons. In at least one embodiment, the plurality of perforations are shaped as one or more of ellipses, circles, squares, rounded corners, rhombuses, rounded rhombuses, rectangles, rounded rectangles, parallelograms, or rounded parallelograms.

[0011] In at least one embodiment, the plurality of perforations define a flow surface porosity within the base, the porosity varying from 20% to 4%.

[0012] As an example, the plurality of chambers have the same depth. As another example, at least two of the plurality of chambers have different depths.

[0013] In at least one embodiment, the flow path piping system includes one or both of an air inlet or an exhaust nozzle having a high aspect ratio.

[0014] Certain embodiments of this disclosure provide a method for forming a flow path duct system for a propulsion system of an aircraft. The method includes the steps of: forming a plurality of perforations through a base between an inner surface and an outer surface, the base defining a flow surface; extending a plurality of supports from the outer surface of the base, the plurality of supports defining a plurality of chambers; fluidly connecting one or more of the plurality of chambers to one or more of the plurality of perforations, wherein the fluid connection step includes: fluidly connecting the one or more of the plurality of chambers to an internal volume defined by the inner surface of the base through the one or more of the plurality of perforations; and securing a backing surface to the plurality of supports, wherein the securing step includes: distributing the plurality of supports between the base and the backing surface.

[0015] Some embodiments of this disclosure provide an aircraft including a propulsion system comprising a flow path piping system as described herein. Attached Figure Description

[0016] Figure 1 A perspective top view of an unmanned aerial vehicle according to an embodiment of the present disclosure is shown.

[0017] Figure 2 A front perspective view of an aircraft according to an embodiment of the present disclosure is shown.

[0018] Figure 3 A side perspective view of an engine according to an embodiment of the present disclosure is shown.

[0019] Figure 4 An internal perspective view of a flow path piping system according to an embodiment of the present disclosure is shown.

[0020] Figure 5 An external perspective view of a flow path piping system according to an embodiment of the present disclosure is shown with the backing surface removed to expose the support and the resulting chamber.

[0021] Figure 6 A partial cross-sectional view of a flow path piping system having a constant depth chamber according to an embodiment of the present disclosure is shown.

[0022] Figure 7 A partial cross-sectional view of a flow path piping system having a constant depth chamber according to an embodiment of the present disclosure is shown.

[0023] Figure 8 A partial cross-sectional view of a flow path piping system having a chamber according to an embodiment of the present disclosure is shown, namely, the chamber having a single-step distribution in depth or two constant depths.

[0024] Figure 9 A partial cross-sectional view of a flow path piping system having a chamber according to an embodiment of the present disclosure is shown, namely, the chamber having a double-step distribution in depth or three constant depths.

[0025] Figure 10 A flowchart illustrating a method for forming a flow path duct system for a propulsion system of an aircraft according to the present disclosure is shown. Detailed Implementation

[0026] The foregoing summary of the invention and the following detailed description of specific embodiments will be better understood when read in conjunction with the accompanying drawings. As used herein, components or steps stated in the singular and beginning with the indefinite article (“a” or “an”) should be understood to not necessarily exclude multiple said components or steps. Moreover, the reference to “one embodiment” is not intended to be construed as excluding additional embodiments that also include the stated features. Furthermore, unless expressly stated otherwise, an embodiment “comprising” or “having” an element or plurality of elements containing a particular condition may include additional elements that do not contain that condition.

[0027] In some smaller vehicles (such as certain unmanned aerial vehicles (UAVs)), or in configurations where a separate liner is impractical, a solution integrated with the underlying structure is required. Consequently, there is a need for an integrated propulsion flow path that can directly incorporate acoustic treatment into the propulsion flow path structure, in contrast to a separate liner being fixed to the structure.

[0028] Some embodiments of this disclosure provide a quiet propulsion flow path piping system comprising: a base having a flow surface; a plurality of supports joined together to define a plurality of chambers isolated from each other; and a backing surface. The supports are located between the base and the backing surface. The base defines a plurality of perforations. The bottom chambers are in volumetric fluid communication with the internal volume of the pipe via one or more perforations. In at least one embodiment, the base, supports, and backing surface together form a monolithic load-bearing structure.

[0029] In at least one embodiment, instead of separately formed parts, the flow path system is integrally formed as a single structure. For example, the flow path system is integrally molded and formed as a single unit (rather than having separate components formed and fixed together). As another example, the flow path system including all component parts is integrally formed by additive manufacturing.

[0030] In at least one embodiment, the plurality of chambers and perforations together form a plurality of Helmholtz resonators for sound attenuation. In at least one embodiment, the plurality of chambers define a shape distribution including triangles, rhombuses, circles, hexagons (honeycomb), or combinations thereof. Furthermore, in at least one embodiment, the plurality of chambers may define a rhomboid shape distribution. In some pipes, the perforations may be elliptical, circular, square, rounded square, rhombus, rounded rhombus, rectangle, rounded rectangle, parallelogram, rounded parallelogram, or combinations thereof. In at least one embodiment, the perforation may be circular. For some embodiments, the perforation may define the flow surface porosity. For example, the porosity may vary from 20% to 4%. In some pipes, the perforation may define the flow surface porosity, for example, a porosity varying from 10% to 6%.

[0031] In at least one embodiment, the depth of the plurality of chambers may be defined as a continuous distribution, a constant distribution, or a stepped distribution with at least one step. In at least one embodiment, the conduit may be formed of titanium, titanium alloy, aluminum, aluminum alloy, stainless steel, or a polymer. For some conduits, the conduit may include a polymer. For some conduit embodiments, the conduit may be a variable geometry having at least one high aspect ratio inlet or outlet.

[0032] Figure 1 A perspective top view of an aircraft 100 (such as an unmanned aerial vehicle (UAV)) according to an embodiment of the present disclosure is illustrated. In at least one embodiment, the UAV 100 includes: a main body or fuselage 101, wings 102, and canards 103. The main body 101 defines an air inlet 110. The air inlet 110 leads to a flow path duct system for a propulsion system. The flow path duct system extends to and penetrates at least a portion of the UAV 100. The flow path duct system is described herein.

[0033] Optionally, the UAV 100 can be connected with Figure 1 The UAV 100 may be shaped, configured, and arranged differently as shown. For example, the UAV 100 may not include a canard. As another example, the wing 102 may be positioned forward of the wing 102 shown in the figure. As yet another example, the UAV 100 may not include a wing. Alternatively, the UAV 100 may include one or more helicopter-shaped rotors, for example.

[0034] Figure 2 A front perspective view of an aircraft 100 according to an embodiment of the present disclosure is illustrated. The aircraft 100 includes a propulsion system 212, which includes, for example, two engines 202, such as two turbofans or turbojet engines. Optionally, the propulsion system 212 may include more engines 202 than shown. The engines 202 are carried by wings 216 of the aircraft 100. In other embodiments, the engines 202 may be carried by a fuselage 218 and / or a tail 220. The tail 220 may also support a horizontal stabilizer 222 and a vertical stabilizer 224. The fuselage 218 of the aircraft 100 defines an interior cabin (including a cockpit). The engines 202 include flow path duct systems, as described herein.

[0035] Aircraft 100 can be with Figure 2 The different shapes, forms, and configurations shown are illustrated. Figure 1 The aircraft 100 shown is merely an example.

[0036] Figure 3A side perspective view of an engine 202 according to an embodiment of the present disclosure is illustrated. In at least one embodiment, the engine 202 is a turbofan or turbojet engine having a housing 300 including an engine inlet 314 leading to a flow path duct system as described herein. The engine inlet 314 may include a leading edge 316 and an inner cylindrical section 320 located at the rear of the leading edge 316 of the engine inlet 314. The inner cylindrical section 320 may provide for guiding airflow (not shown) into the engine inlet 314 and through the boundary surface or wall of the engine 202. The inner cylindrical section 320 may be positioned relatively close to one or more fan blades ( Figure 3 (Not shown). In at least one embodiment, the inner cylinder section 320 may also be configured as an acoustic structure with multiple perforations in the inner panel of the inner cylinder section 320 for absorbing noise generated by the rotating fan blades and / or noise generated by airflow entering the engine intake 314 and passing through the engine 202. In at least one embodiment, the inner cylinder section 320 includes and / or may be configured as a flow path duct system as described herein.

[0037] Figure 4 An internal perspective view of a flow path piping system 400 according to an embodiment of the present disclosure is shown. Figure 5 An external perspective view of a flow path piping system 400 according to an embodiment of the present disclosure is shown with the backing surface removed to expose the support and the resulting chamber.

[0038] Reference Figure 4 and Figure 5 In at least one embodiment, the flow path piping system 400 is in Figure 1 Within the UAV 100 shown. For example, Figure 1 The air inlet 110 shown leads to or forms the air inlet of the flow path duct system 400. In at least one other embodiment, the flow path duct system 400 is located in Figure 2 and Figure 3 Within the engine 202 shown. For example, Figure 3 The engine air intake 314 shown leads to or forms the air intake of the flow path duct system 400.

[0039] The flow path system 400 provides a quiet propulsion flow path system. The flow path system 400 includes an inner surface 428 that defines a flow surface 410. For example, a base 426 includes an inner surface 428 that defines the flow surface 410. Fluid (e.g., air) travels over and along the flow surface 410. A support member 420 extends opposite to the base 426 (e.g., at edges 422 and outer surfaces). The support member 420 may include: a frame, beam, rib, fin, wall, etc.

[0040] Support member 420 defines a plurality of chambers 421. For example, chamber 421a is defined between first support member 420a and second support member 420b. Chamber 421b is defined between second support member 420b and third support member 420c. Support members 420 can be similarly shaped and formed. Support member 420 can be an upright fin, wall, beam, rib, etc.

[0041] The flow path system 400 also includes a backing surface 430 and a plurality of perforations 440. For example, the backing surface 430 is disposed above the exterior of the support 420, the chamber 421, and / or the perforations 440. For example, the perforations 440 may be formed in the base 426. As an example, the support 420 extends from the base 426 providing the flow surface 410. In at least one embodiment, the support 420 is or otherwise includes a fin 427 extending from the base 426. The chamber 421 is defined between the base 426 and the fin 427. The perforations 440 are formed in and / or through the base 426. Thus, a fluid flow path extends between the chamber 421, the perforations 440, and the internal volume 435 of the flow path system 400. The backing surface 430 may be a plate, skin, etc., disposed above the support 420 and the chamber 421.

[0042] The chamber 421 extends from the outer surface of the base 426 (opposite to the flow surface 410) and thus extends away from the internal volume 435. A perforation 440 is formed in the base 426 and is in fluid communication with the internal volume 435. Therefore, a fluid flow path extends from the chamber 421, through the perforation 440 in the base 426, and into the internal volume 435.

[0043] In at least one embodiment, the depth 423 of chamber 421 is constant throughout the flow path piping system 400. That is, the distribution of the depth 423 of chamber 421 can be the same throughout the flow path piping system 400. Optionally, the depths of some chambers 421 can be different. In at least one embodiment, Figure 4 and Figure 5 The flow path duct system 400 shown provides a single, complex geometry air inlet structure that can be manufactured to provide sound attenuation.

[0044] In at least one implementation, such as Figure 5 As shown, the support member 420 includes crossbeams, beams, ribs, panels, walls, or fins 427 that intersect to form a plurality of repeating chambers 421. The support member 420 defines the outer boundary of the chambers 421, which may have various shapes and sizes.

[0045] In at least one embodiment, the flow path system 400 is a propulsion system for an aircraft. The flow path system 400 includes a base 426 defining a flow surface 410 (such as on an inner surface 428). The base 426 includes an inner surface 428 and an outer surface 432. A plurality of perforations 440 are formed between the inner surface 428 and the outer surface 432, penetrating the base 426. A support member 420 defines a chamber 421. The support member 420 extends outwardly from the outer surface 432 of the base 426. One or more of the plurality of chambers 421 are in fluid communication with one or more of the plurality of perforations 440. A backing surface 430 is secured to the plurality of supports 420. The supports 420 are disposed between the base 426 and the backing surface 430. One or more of the plurality of chambers 421 are in fluid communication with an internal volume 435 defined by the inner surface 428 of the base 426 through one or more of the plurality of perforations 440.

[0046] In at least one embodiment, the base 426, support 420, and backing surface 430 are integrally formed into a single load-bearing structure. For example, the base 426, support 420, and backing surface 430 are additively manufactured together. That is, the flow path piping system 400, including its components, is integrally formed by an additive manufacturing process.

[0047] In at least one embodiment, each chamber in the chamber 421 is in fluid communication with at least one perforation 440, and vice versa. In at least one embodiment, the chambers 421 and the perforations 440 cooperate to provide a plurality of Helmholtz resonators.

[0048] Figure 6 A partial cross-sectional view of a flow path piping system 400 having a constant depth chamber according to an embodiment of the present disclosure is shown. Figure 6 As shown, the flow path duct system 400 includes an air inlet 401. The depth (or height) 423 of the chamber 421 can be constant along the length 460 of the flow path duct system 400.

[0049] Figure 7 A partial cross-sectional view of a flow path piping system 400 having a constant depth chamber 421 according to an embodiment of the present disclosure is shown. Figure 7 As shown, the flow path piping system 400 can be an exhaust nozzle 403. Again, the depth (or height) 423 of the chamber 421 can be constant along the length 462 of the flow path piping system 400.

[0050] Reference Figure 6 and Figure 7Although the depth 423 of the chamber 421 can be the same throughout the flow path piping system 400, the width 429 can be different. For example, the first set of chambers 421 can have a different first width than the second set of chambers 421. Alternatively, the width 429 of the chamber 421 can be the same everywhere.

[0051] Figure 8 A partial cross-sectional view of a flow path piping system 400 according to an embodiment of the present disclosure is illustrated, wherein the chambers have a single-step distribution at depth 423 or two constant depths. For example, the depth 423 of the first set of chambers 421c is different from the depth 423 of the second set of chambers 421d. A step 425 defines the transition between the first set of chambers 421c and the second set of chambers 421d. As shown, the depth 423 of the first set of chambers 421c is greater than the depth 423 of the second set of chambers 421d. Alternatively, the depth 423 of the second set of chambers 421d may be greater than the depth 423 of the first set of chambers 421c.

[0052] Figure 9 A partial cross-sectional view of a flow path piping system 400 according to an embodiment of the present disclosure is shown, wherein the chambers have a double-step distribution in depth or three constant depths. For example, the depth 423 of the first set of chambers 421e differs from the depth 423 of the second set of chambers 421f, which in turn differs from the depth 423 of the third set of chambers 421g. Step 431 defines the transition between the first set of chambers 421e and the second set of chambers 421f. Step 433 defines the transition between the second set of chambers 421f and the third set of chambers 421g. As shown, the depth 423 of the first set of chambers 421e is greater than the depth 423 of the second set of chambers 421f. Furthermore, the depth 423 of the second set of chambers 421g is greater than the depth 423 of the third set of chambers 421g. Optionally, the depth 423 of the second set of chambers 421f can be greater than the depth 423 of the first set of chambers 421e, and / or the depth 423 of the third set of chambers 421g can be greater than the depth 423 of the second set of chambers 421f.

[0053] Reference Figures 4 to 9 Some embodiments provide a flow path piping system 400 and a method of manufacturing the flow path piping system 400. In at least one embodiment, the method includes the step of additively manufacturing a piping geometry into a monolithic structure, wherein the geometry includes: a flow surface 410, a support member 420 defining a plurality of chambers 421 that are isolated from each other, and a backing surface 430. In at least one embodiment, the support member 420 is located between the flow surface 410 and the backing surface 430.

[0054] In at least one embodiment, the flow path system 400 and the method of forming the flow path 400 further include the plurality of perforations 440. The perforations 440 are in fluid communication with one or more chambers 421. In at least one embodiment, the plurality of perforations 440 may be added to the flow surface 410, in contrast to adding them during an additive manufacturing step.

[0055] As mentioned above, the support member 420 is located between the base 426 and the backing surface 430. In at least one embodiment, the support member 420 can be joined together. For example, the support member 420 can be fastened together. In at least one embodiment, the flow surface 410, the support member 420, and the backing surface 430 define chambers 421 within the flow path system 400. The chambers 421 are isolated from each other. In at least one embodiment, the base 426, the support member 420, and the backing surface 430 are collectively formed as a monolithic load-bearing structure. In at least one embodiment, the monolithic structure can be additively manufactured. In at least one embodiment, the flow path system 400 can be a primary load-bearing structure, resulting in an integrated design with a reduced component count and reduced complexity.

[0056] The base 426 includes a plurality of perforations 440. One or more chambers 421 are in fluid communication with the internal volume 435 of the flow path system 400 through the perforations 440. The perforations 440 provide acoustic flow paths to the underlying isolation chambers 421 to effectively attenuate acoustic energy. In at least one embodiment, the chambers 421 and the perforations 440 together form a plurality of Helmholtz resonators configured to attenuate sound.

[0057] The perforation 440 can have various sizes and shapes. For example, the perforation 440 can be formed as an ellipse, circle, square, rounded square, rhombus, rounded rhombus, rectangle, rounded rectangle, parallelogram, rounded parallelogram, or a combination thereof. A circular perforation 440 has chamfered joints, edges, etc., to provide a smooth transition. In at least one embodiment, the perforation 440 can be circular.

[0058] In at least one embodiment, the number of sizes of the perforations 440 (e.g., surface area and perforation volume) defines the porosity of the flow surface 410. For example, the porosity defined by the perforations 440 (i.e., the total volume of open spaces within the flow path system 400) ranges from about 20% (e.g., between 18% and 22%), about 15% (e.g., between 13% and 17%), about 10% (e.g., between 8% and 12%), about 8% (e.g., between 6% and 10%), about 6% (e.g., between 4% and 8%), or about 5% (e.g., between 3% and 7%) to about 4% (e.g., between 2% and 5%), or any combination thereof. In at least one embodiment, for example, the porosity ranges from about 10% to about 6%, or about 8%.

[0059] In at least one embodiment, the plurality of chambers 421 define a shape distribution including: triangular, rhomboid, circular, hexagonal (honeycomb), or combinations thereof. For example, such as Figure 5 As shown, chamber 421 has a shape 490 in the form of a rhombus. In at least one embodiment, for example, chamber 421 defines a distribution of rhomboid shapes, such as... Figure 5 As shown, the support member 420 defines the outer envelope of the shape of the chamber 421. In this way, the support member 420 provides load transfer and structural support for the flow path piping system 400 and defines the envelope of the chamber 421.

[0060] In at least one embodiment, the dimensions and spacing of the perforation 440 and the chamber 421 are tuned for custom frequency attenuation using methods known in the art, such as noise propagation codes (an example being ACoustic TRANsmission). Alternatively, the theoretical method described in Wu et al., Noise Attenuation Performance of a Helmholtz Resonator Array Consist of Several Periodic Parts, 17 Sensors 2029 (2017), can be used. In at least one embodiment, the depth of the chamber can be varied for sound attenuation optimization. In some embodiments, the depth 423 of the chamber 421 defines a continuous distribution, a constant distribution, or a stepped distribution having at least one step (e.g., one step, two steps, or more steps).

[0061] In at least one embodiment, the material of the flow path piping system 400 can be changed according to actual use and environmental conditions. For example, the flow path piping system 400 may be formed of titanium, titanium alloy, aluminum, aluminum alloy, stainless steel, one or more polymers, etc.

[0062] In at least one embodiment, the flow path system 400 includes variable geometry. For example, the flow path system 400 includes: an inlet flow path, an outlet, a nozzle, a partial flow path, and / or a complete flow path. In at least one embodiment, the inlet (such as...) Figure 6 The air inlet 401 shown or the outlet (such as...) Figure 7 The exhaust nozzle 403 shown includes a high aspect ratio. Aspect ratio is defined as the ratio of the width to the height of the flow path system 400, wherein an aspect ratio greater than two (i.e., the width is at least twice the height) is a high aspect ratio of the flow path system 400. In at least one embodiment, the air inlet 401 and the exhaust nozzle 402 form a high aspect ratio.

[0063] While the fluid path piping system 400 described herein may be monolithic in terms of acoustic treatment and load-bearing structure, a fully assembled fluid path piping system 400 integrated into a vehicle (such as an aircraft) may include several different monolithic piping geometry segments (e.g., inlet, nozzle, upper section, lower section), in contrast to a large segment due to additive manufacturing and installation constraints.

[0064] In at least one embodiment, instead of additively manufacturing the flow surface 410 having multiple perforations 440, different methods can be used to form the perforations 440. For example, the perforations 440 can be formed by drilling, laser cutting, vaporization, ablation, chemical treatment, etc.

[0065] As described herein, certain embodiments of this disclosure provide a quiet propulsion flow path piping system 400, comprising: a flow surface 410, a plurality of support members 420 defining a plurality of chambers 421 isolated from each other, and a backing surface 430. The support members 420 are located between the flow surface 410 and the backing surface 430. For example, the support member 420 is clamped between the flow surface 410 and the backing surface 430. A base 426 having the flow surface 410 includes a plurality of perforations 440 such that at least one bottom chamber 421 is in fluid communication with an internal volume 435 through the perforations 440. In at least one embodiment, the flow surface 410, the support members 420, and the backing surface 430 are collectively formed as a monolithic support structure.

[0066] Figure 10 A flowchart illustrating a method for forming a flow path duct system for a propulsion system of an aircraft according to the present disclosure is shown. (Refer to...) Figures 1 to 10The method includes the following steps: at 500, forming a plurality of perforations 440 through a base 426 between an inner surface 428 and an outer surface 432, the base defining a flow surface 410; at 502, extending a plurality of support members 420 from the outer surface 432 of the base 426, the plurality of support members defining a plurality of chambers 421; at 504, fluidly connecting one or more of the plurality of chambers 421 to one or more of the plurality of perforations 440, wherein the fluid connection step 504 includes: fluidly connecting the one or more of the plurality of chambers 421 to an internal volume 435 defined by the inner surface 428 of the base 426 through the one or more of the plurality of perforations 440; and at 506, securing a backing surface 430 to the plurality of support members 420, wherein the securing step 506 includes: disposing the plurality of support members 420 between the base 426 and the backing surface 430.

[0067] In at least one embodiment, the method further includes the step of integrally forming the base 426, the plurality of support members 420, and the backing surface 430 into a single load-bearing structure. As another example, the integral forming step includes additively manufacturing the base 426, the plurality of support members 420, and the backing surface 430 together.

[0068] In at least one embodiment, step 504 of the fluid connection includes: fluidly connecting each of the plurality of chambers 421 to at least one of the plurality of perforations 440.

[0069] In at least one embodiment, the forming step 500 includes forming the plurality of perforations 440 within the base to define the porosity of the flow surface, the porosity varying from 20% to 4%.

[0070] In at least one embodiment, the method includes the step of forming the flow path duct system 400 as one or both of an air inlet or an exhaust nozzle with a high aspect ratio.

[0071] It has been found that the implementation of the flow path piping system 400 described herein reduces acoustic noise and can be used as a main load-bearing structure.

[0072] Furthermore, this disclosure includes implementations according to the following provisions:

[0073] Clause 1. A flow path piping system for a propulsion system of an aircraft, the flow path piping system comprising:

[0074] A base defining a flow surface, wherein the base has an inner surface and an outer surface, wherein a plurality of perforations penetrating the base are formed between the inner surface and the outer surface;

[0075] A plurality of support members defining a plurality of chambers, wherein the plurality of support members extend outwardly from an outer surface of the base, and wherein one or more of the plurality of chambers are in fluid communication with one or more of the plurality of perforations; and

[0076] The backing surface is fixed to the plurality of support members.

[0077] The plurality of support members are disposed between the base and the backing surface, and

[0078] One or more of the plurality of chambers are in fluid communication with the internal volume defined by the inner surface of the base through one or more of the plurality of perforations.

[0079] Clause 2. The flow path piping system according to Clause 1, wherein the base, the plurality of supports and the backing surface are integrally formed into a single load-bearing structure.

[0080] Clause 3. The flow path piping system according to Clause 2, wherein the base, the plurality of supports, and the backing surface are additively manufactured together.

[0081] Clause 4. A flow path piping system according to any one of Clauses 1 to 3, wherein each of the plurality of chambers is in fluid communication with at least one of the plurality of perforations.

[0082] Clause 5. The flow path system as described in Clause 4, wherein the plurality of chambers and the plurality of perforations cooperate to provide a plurality of Helmholtz resonators.

[0083] Clause 6. A flow path piping system according to any one of Clauses 1 to 5, wherein the plurality of chambers are shaped as one or more of triangles, rhombuses, circles and hexagons.

[0084] Clause 7. The flow path piping system according to any one of Clauses 1 to 6, wherein the plurality of perforations are circular.

[0085] Clause 8. A flow path piping system according to any one of Clauses 1 to 7, wherein the plurality of perforations within the base define a flow surface porosity ranging from 20% to 4%.

[0086] Clause 9. A flow path piping system according to any one of Clauses 1 to 8, wherein the plurality of chambers have the same depth.

[0087] Clause 10. A flow path piping system according to any one of Clauses 1 to 9, wherein at least two of the plurality of chambers have different depths.

[0088] Clause 11. The flow path piping system according to any one of Clauses 1 to 10, wherein the flow path piping system further includes one or both of an inlet or an exhaust nozzle having a high aspect ratio.

[0089] Clause 12. A method for forming a flow path duct system for a propulsion system of an aircraft, the method comprising the steps of:

[0090] Multiple perforations penetrating the base are formed between the inner and outer surfaces, the base defining a flow surface;

[0091] A plurality of support members extend from the outer surface of the base, the plurality of support members defining a plurality of chambers;

[0092] Fluidly connecting one or more of the plurality of chambers to one or more of the plurality of perforations, wherein the fluid connection step includes: fluidly connecting the one or more of the plurality of chambers to the internal volume defined by the inner surface of the base through the one or more of the plurality of perforations; and

[0093] The backing surface is fixed to the plurality of support members, wherein the fixing step includes: disposing the plurality of support members between the base and the backing surface.

[0094] Clause 13. The method according to Clause 12, the method further comprising the step of: integrally forming the base, the plurality of supports and the backing surface into a single load-bearing structure.

[0095] Clause 14. The method according to Clause 12 or 13, wherein the integrally formed step comprises: additively manufacturing the base, the plurality of supports, and the backing surface together.

[0096] Clause 15. The method according to any one of Clauses 12 to 14, wherein the step of fluid connection comprises: fluidly connecting each of the plurality of chambers to at least one of the plurality of perforations.

[0097] Clause 16. The method according to any one of Clauses 12 to 15, wherein the forming step comprises: forming the plurality of perforations within the base to define a flow surface porosity, the porosity varying from 20% to 4%.

[0098] Clause 17. The method according to any one of Clauses 12 to 16, the method further comprising the step of: forming the flow path piping system as one or both of an inlet or an exhaust nozzle having a high aspect ratio.

[0099] Clause 18. An aircraft comprising:

[0100] A propulsion system including a flow path piping system, the flow path piping system comprising:

[0101] A base defining a flow surface, wherein the base has an inner surface and an outer surface, wherein a plurality of perforations penetrating the base are formed between the inner surface and the outer surface;

[0102] A plurality of supports defining a plurality of chambers; the plurality of supports extending outwardly from the outer surface of the base, and wherein each of the plurality of chambers is in fluid communication with at least one of the plurality of perforations; and

[0103] The backing surface is fixed to the plurality of support members.

[0104] The plurality of support members are disposed between the base and the backing surface, and

[0105] The plurality of chambers are in fluid communication with the internal volume defined by the inner surface of the base through the plurality of perforations.

[0106] Clause 19. The aircraft as described in Clause 18, wherein the base, the plurality of supports, and the backing surface are integrally formed into a single load-bearing structure.

[0107] Clause 20. An aircraft as described in Clause 18 or 19, wherein the plurality of perforations define a flow surface porosity within the base, the porosity varying from 20% to 4%.

[0108] As described herein, embodiments of this disclosure provide systems and methods for efficiently and effectively reducing noise associated with various components such as aircraft engines. Furthermore, embodiments of this disclosure, for example, provide relatively simple systems and methods for reducing noise related to aircraft.

[0109] While various spatial and directional terms (such as top, bottom, lower, middle, horizontal, horizontal, vertical, front, etc.) may be used to describe embodiments of this disclosure, it should be understood that these terms are used only relative to the orientation shown in the figures. The orientation may be reversed, rotated, or otherwise changed, such that the upper part is the lower part, the lower part is the upper part, the horizontal becomes the vertical, etc.

[0110] As used herein, structures, constraints, or components “configured” to perform a task or operation are specifically formed, constructed, or adapted in a manner corresponding to that task or operation. For clarification and to avoid ambiguity, it can only be modified to state that the object performing the task or operation is not “configured” to perform the task or operation as used herein.

[0111] It should be understood that the above description is intended to be illustrative and not limiting. For example, the above embodiments (and / or aspects thereof) may be used in combination with each other. Furthermore, many modifications may be made to adapt to specific situations or materials that are relevant to the teachings of the various embodiments of this disclosure without departing from the scope of this disclosure. While the scale and type of the materials described herein are intended to limit the parameters of the various embodiments of this disclosure, these embodiments are by no means limiting, but rather exemplary. Many other embodiments will be apparent to those skilled in the art upon review of the above description. Therefore, the scope of the various embodiments of this disclosure should be determined with reference to the appended claims, together with the full scope of the equivalents of such claims. In the appended claims and the detailed description herein, the terms “including” and “containing” are used as common English equivalents of the term “comprising,” and the term “in which” is used as a common English equivalent of the term “wherein.” Furthermore, the terms “first,” “second,” and “third,” etc., are used merely as labels and are not intended to impose numerical requirements on them. Furthermore, the limitations of the above claims are not written in the form of device plus function, and are not intended to be interpreted based on 35 U.SC §112(f), unless such limitation of claims is explicitly followed by the phrase "device for..." after a functional statement lacking further structure.

[0112] This written description uses examples to disclose various embodiments of this disclosure, including the best mode, and also enables any person skilled in the art to embody and practice the various embodiments of this disclosure, including making and using any apparatus or system and performing any incorporated method. The patentable scope of the various embodiments of this disclosure is defined by the claims and may include other examples that would occur to a person skilled in the art. Such other examples are within the scope of the claims if they have structural components that are not different from the literal language of the claims, or if the examples include equivalent structural components that are not substantially different from the literal language of the claims.

Claims

1. A flow path piping system for a propulsion system of an aircraft, the flow path piping system comprising: An air inlet that defines a single fluid path and has a first high aspect ratio; An exhaust nozzle having a second high aspect ratio; A base defining a flow surface, wherein the base has an inner surface and an outer surface, wherein a plurality of perforations penetrating the base are formed between the inner surface and the outer surface; A plurality of support members defining a plurality of chambers, wherein the plurality of support members extend outwardly from the outer surface of the base, and wherein one or more of the plurality of chambers are in fluid communication with one or more of the plurality of perforations; and The backing surface is fixed to the plurality of support members. The plurality of support members are disposed between the base and the backing surface, and One or more of the plurality of chambers are in fluid communication with the internal volume defined by the inner surface of the base through one or more of the plurality of perforations.

2. The flow path duct system of claim 1, wherein, The base, the plurality of support members, and the backing surface are integrally formed into a single load-bearing structure.

3. The flow path duct system of claim 1, wherein, Each of the plurality of chambers is in fluid communication with at least one of the plurality of perforations.

4. The flow path piping system according to claim 3, wherein, The multiple chambers and the multiple perforations cooperate to provide multiple Helmholtz resonators.

5. The flow path piping system according to claim 1, wherein, The multiple chambers are shaped as one or more of triangles, rhombuses, circles, and hexagons.

6. The flow path piping system according to claim 1, wherein, The multiple perforations are circular.

7. The flow path piping system according to claim 1, wherein, The plurality of perforations define the porosity of the flow surface within the base, the porosity varying from 20% to 4%.

8. The flow path piping system according to claim 1, wherein, The multiple chambers have the same depth.

9. A method for forming a flow path duct system for a propulsion system of an aircraft, the method comprising the following steps: The flow path system is formed between the air inlet and the exhaust nozzle, wherein the air inlet defines a single fluid path, and each of the air inlet and the exhaust nozzle has a high aspect ratio; Multiple perforations penetrating the base are formed between the inner and outer surfaces, the base defining a flow surface; A plurality of support members extend from the outer surface of the base, the plurality of support members defining a plurality of chambers; Fluidly connecting one or more of the plurality of chambers to one or more of the plurality of perforations, wherein the fluid connection step includes: fluidly connecting the one or more of the plurality of chambers to the internal volume defined by the inner surface of the base through the one or more of the plurality of perforations; and The backing surface is fixed to the plurality of support members, wherein the fixing step includes: disposing the plurality of support members between the base and the backing surface.

10. The method according to claim 9, further comprising the following step: The base, the plurality of support members, and the backing surface are integrated into a single load-bearing structure.

Images