Variable exhaust valve assembly

Abstract

Exemplary variable exhaust valve assemblies for gas turbine engines are disclosed herein. An example variable exhaust valve assembly includes a port extending radially outward from a main flow path of a gas turbine engine, a door at an outlet of the port, and an acoustic black hole (ABH) assembly coupled to the door. The ABH assembly includes a body and a plurality of plates coupled to an interior surface of the body. The body defines a cavity having a depth. Each of the plurality of plates has a surface area, and the plurality of plates are arranged such that the surface areas of the plurality of plates vary along the depth in a radially outward direction of the gas turbine engine.

Description

Technical Field

[0001] The present disclosure relates generally to turbine engines and, more particularly, to variable exhaust valve assemblies. Background Art

[0002] Turbine engines are one of the most widely used power generation technologies, commonly used in aircraft and power generation applications. For example, a turbofan engine is a type of turbine engine that typically includes a fan and a core in fluid communication with each other. The turbine engine core typically includes a compressor section, a combustion section, a turbine section coaxially located with the compressor section, and an exhaust section in serial flow order. Typically, a casing or outer shell surrounds the turbine engine core. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Figure 1 is a cross-sectional view of an example gas turbine engine in which examples disclosed herein may be implemented.

[0004] Figure 2 yes Figure 1 A partial cross-sectional side view of a compressor of a gas turbine engine is shown including a variable exhaust valve assembly.

[0005] Figure 3A is included Figure 2 Side view of the variable exhaust valve assembly of the compressor.

[0006] Figure 3B is included Figure 2 Cross-sectional front view of the variable exhaust valve assembly of a compressor.

[0007] Figure 4A is a partial cross-sectional side view of an example first variable exhaust valve assembly including an example first acoustic black hole assembly according to the teachings disclosed herein.

[0008] Figure 4B is a partial cross-sectional side view of an example second variable exhaust valve assembly including an example second acoustic black hole assembly according to the teachings disclosed herein.

[0009] Figure 5A is a cross-sectional front view of an example third variable exhaust valve assembly including an example third acoustic black hole assembly according to the teachings disclosed herein.

[0010] Figure 5B is a cross-sectional front view of an example fourth variable exhaust valve assembly including an example fourth acoustic black hole assembly according to the teachings disclosed herein.

[0011] Figure 6 is a cross-sectional front view of an example fifth variable exhaust valve assembly including an example fifth acoustic black hole assembly according to the teachings disclosed herein.

[0012] Figure 7 is a cross-sectional front view of an example sixth variable exhaust valve assembly including an example sixth acoustic black hole assembly according to the teachings disclosed herein.

[0013] Figure 8A 、 8B , 8C, 8D, 8E, 8F, 8G, 8H, 8I, and 8J illustrate various example acoustic black hole assemblies that may be implemented with any of the example variable exhaust valve assemblies disclosed herein. Figure 8A 、 8B , 8C, 8D, 8E, 8F, 8G, 8H, 8I and 8J have various panel arrangements, damping materials, structural damping layers, perforated panels, wire mesh and diaphragm panels.

[0014] Figure 9 An example acoustic black hole assembly is shown having a cylindrical shape.

[0015] Figure 10 An example acoustic black hole assembly is shown having a rectangular parallelepiped shape.

[0016] Figure 11A 、 11B , 11C, 11D, and 11E illustrate various example acoustic black hole assemblies that may be implemented with any of the example variable exhaust valve assemblies disclosed herein. Figure 11A 、 11B The example acoustic black hole assemblies of 11C, 11D, and 11E have plates and perforated plates with various arrangements of inner and outer diameters.

[0017] Figure 12A An example acoustic black hole assembly is shown that may be implemented with any of the example variable exhaust valve assemblies disclosed herein.

[0018] Figure 12B Shown Figure 12A An example plate of an example acoustic black hole assembly having a tapered peripheral section connected to an outer sidewall.

[0019] Figure 12C Shown Figure 12A An example plate of an example acoustic black hole assembly having a peripheral section having multiple connections to an outer sidewall.

[0020] Figure 12D Shown Figure 12A Example panels of an example acoustic black hole assembly constructed from materials of varying density and / or elasticity.

[0021] Figure 13A An example acoustic black hole assembly having a perforated plate is shown, which may be implemented in any of the example variable exhaust valve assemblies disclosed herein.

[0022] Figure 13B yes Figure 13A A top view of an example plate for the Acoustic Black Hole assembly.

[0023] Figure 14A 、 14B , 14C, and 14D illustrate various example acoustic black hole assemblies that may be implemented with any of the example variable exhaust valve assemblies disclosed herein. Figure 14A 、 14B , 14C and 14D have various chamber and plate arrangements.

[0024] Figure 15 An example acoustic black hole assembly with a branching chamber is shown, which may be implemented with any of the example variable exhaust valve assemblies disclosed herein.

[0025] The accompanying drawings are not drawn to scale. On the contrary, the thickness of a layer or region may be magnified in the accompanying drawings. Although the accompanying drawings show layers and regions with clear lines and boundaries, some or all of these lines and / or boundaries may be idealized. In fact, boundaries and / or lines may be unobservable, mixed and / or irregular. In general, the same reference numerals will be used to refer to the same or similar parts throughout the accompanying drawings and the accompanying written description. As used in this patent, stating that any component (e.g., layer, film, zone, region or plate) is located on another component in any way (e.g., positioned on, located at, arranged on or formed on another component, etc.) indicates that the referenced component contacts another component, or that the referenced component is located above another component and there are one or more intermediate components therebetween. As used herein, unless otherwise stated, connection references (e.g., attachment, coupling, connection and engagement) can include intermediate members between the elements referenced by the connection reference and / or the relative motion between these elements. Therefore, connection references do not necessarily mean that two elements are directly connected and / or fixed to each other. As used herein, the definition stating that any component is "in contact with" another component means that there is no intermediate component between the two components. DETAILED DESCRIPTION

[0026] Unless expressly stated otherwise, descriptors used herein, such as "first," "second," "third," etc., do not in any way imply or otherwise indicate any priority, physical order, arrangement in a list, and / or ordering, but are merely used as labels and / or arbitrary names to distinguish elements to facilitate understanding of the disclosed examples. In some examples, the descriptor "first" may be used to refer to an element in the detailed description, while the same element may be referred to by different descriptors, such as "second" or "third," in the claims. In such cases, it should be understood that these descriptors are only used to clearly identify those elements that may share the same name.

[0027] Throughout the specification and claims, approximating language is used to modify any quantitative representation that can be permitted to vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by one or more terms (e.g., "about," "approximately," and "substantially") is not limited to the precise value specified. In some examples used herein, the term "substantially" is used to describe a relationship between two parts that is within three degrees of the stated relationship (e.g., a substantially collinear relationship is within three degrees of linearity, a substantially perpendicular relationship is within three degrees of perpendicularity, a substantially identical relationship is within three degrees of the same, a substantially flush relationship is within three degrees of flushness, etc.). In some examples used herein, the term "objectively" is used to mean having a large or significant effect.

[0028] As used herein, the terms "upstream" and "downstream" refer to locations along a fluid flow path relative to the direction in which the fluid flows from a first location to a second location. For example, with respect to fluid flow, "upstream" refers to a first location from which the fluid flows, while "downstream" refers to a second location toward which the fluid flows. For example, with respect to a gas turbine engine, the compressor is located upstream of the turbine relative to the direction of air flow through the engine.

[0029] Various terms are used herein to describe the orientation of features. Generally, the drawings are labeled with reference to the axial, radial, and circumferential directions of the vehicle with respect to features, forces, and moments. Generally, the drawings are labeled with a set of axes, including an axial axis A, a radial axis R, and a circumferential axis C.

[0030] In the following detailed description, reference is made to the accompanying drawings forming a part of this paper, in which specific examples that can be put into practice are shown by way of example. The description of these examples is detailed enough to enable those skilled in the art to practice this theme, and it should be understood that other examples can be used. Therefore, the following detailed description is provided to describe example embodiments and should not be construed as limiting the scope of the theme described in this disclosure. Certain features of the different aspects described below can be combined to form some new aspects of the theme discussed below.

[0031] A turbine engine, also referred to herein as a gas turbine engine, is a continuous flow internal combustion engine that uses atmospheric air as a flowing fluid. In operation, atmospheric air enters the turbine engine via a fan and flows through a compressor section, where one or more compressors gradually compress (e.g., pressurize) the air until the air reaches the combustion section. In the combustion section, the pressurized air is combined with fuel and ignited to produce a high-temperature, high-pressure airflow (e.g., hot combustion gases), which then enter the turbine section. The hot combustion gases expand as they flow through the turbine section, causing the rotating blades of one or more turbines to rotate. The rotating blades of the turbine generate a spool work output that powers the corresponding compressor. A spool is a combination of a compressor, a shaft, and a turbine. A turbine engine typically includes multiple spools, such as a high-pressure spool (e.g., an HP compressor, a shaft, and a turbine) and a low-pressure spool (e.g., an LP compressor, a shaft, and a turbine). However, in additional or optional examples, a turbine engine may include one spool or more than two spools.

[0032] During low-speed operation of a turbine engine (e.g., during startup and / or shutdown), the balance of the engine is adjusted. In many cases, a delay is required to allow the spool to adapt (e.g., it takes a certain amount of time for the speed to adjust to the new balance). However, the compressor continues to provide pressurized air for fuel combustion during operation. This result may cause the turbine to stop generating power to drive the compressor, thereby causing the compressor itself to stop compressing air. Therefore, throttling changes may cause compressor instabilities, such as compressor stall and / or compressor surge. Compressor stall is an abnormal airflow condition caused by aerodynamic stall of the rotor blades within the compressor. Compressor stall causes the air flowing through the compressor to slow down or stagnate. In some cases, the interruption of air flow as the air passes through the various stages of the compressor can cause compressor surge. Compressor surge refers to a stall that causes an interruption of air flow through the compressor (e.g., complete interruption, partial interruption, other partial interruption, etc.).

[0033] Gas turbine engines include a variable bleed valve (VBV) integrated into the compressor (e.g., at the downstream end of the LP compressor) to improve efficiency and limit potential stalls. The VBV enables the turbine engine to bleed air from the compressor section during operation. An example VBV assembly includes a VBV port (e.g., an opening, an air bleed slot, etc.), comprising a VBV cavity extending from the compressor casing and a VBV door that is actuated to open. In other words, the VBV is configured as a cavity with a door that opens to provide an exhaust flow path to bleed compressed air between the gas turbine's supercharger (e.g., the low-pressure compressor) and the core engine compressor. For example, the VBV door can be actuated during a speed-to-speed mismatch between the LP and HP spools due to a deviation from their designed speed balance. Speed-to-speed mismatch occurs during low-speed operation or during deceleration, for example, when the HP spool decelerates too early or out of proportion or correlation with the LP spool, causing the mass flow rate through the core to lose its intended balance. This results in the LP compressor trying to pump an excessively high mass flow rate to the HP compressor and potentially causing the HP compressor to surge, or the reduced HP core mass flow may cause the LP compressor to stall. To help balance this mismatch, the VBV allows some of the mass flow from the LP compressor (supercharger) to bypass the core compressor to maintain normal operation of the turbomachinery in the engine. In other words, opening the VBV port allows the LP spool to maintain its speed while reducing the amount of air flowing through the HP compressor by directing some of the flow to other engine components (e.g., bypass, turbine, turbine exhaust area, etc.). Thus, the VBV port allows the LP spool (e.g., supercharger) to operate at a lower operating throttle line and reduce the likelihood of potential instability or stall conditions.

[0034] In some VBV ports, the VBV door is not flush with the compressor casing, leaving the exhaust cavity open to the main flow path within the compressor. When the VBV door is closed, air from the main flow path flows through the VBV cavity opening. This causes the VBV port to acoustically resonate at a fixed frequency or a set of frequencies, similar to blowing into an empty bottle. This phenomenon is known as resonance. More specifically, the shear layer of the airflow separates from the upstream edge and strikes the downstream edge of the VBV port, generating acoustic feedback. This shear layer feedback resonates with the air within the VBV cavity, generating an energetic acoustic tone emanating from the exhaust cavity. Depending on the geometry of the VBV cavity, this oscillation / acoustic tone can be amplified and / or acoustically excite the air in the engine core. At certain resonant frequencies, the acoustic excitation can also resonate with mechanical vibrations within the LP compressor's rotor system (e.g., rotor blades, rotor disks, blisks (integrated rotor disks and blades), etc.). In some cases, the mechanical vibrations propagate upstream along the rotor system toward one of the rotor disks (e.g., the initial rotor disk) and / or intensify. This resonant mechanical excitation of the LP compressor hardware can lead to increased stress levels and induce crack formation, damaging the rotor system and / or degrading supercharger performance. For example, one or more rotor blades of a rotor stage may crack due to excessive mechanical vibrations caused by the acoustic resonance of the closed VBV port (e.g., the VBV cavity). Therefore, a new VBV assembly is needed to reduce the resonant frequency of the VBV cavity when the VBV door is closed.

[0035] Disclosed herein are example VBV assemblies, including an acoustic black hole (ABH) assembly coupled to a VBV door, to reduce VBV cavity acoustic resonance response. More specifically, the example ABH assembly can receive and suppress incident (e.g., incoming) acoustic wave energy, causing the waves to be reflected as significantly attenuated acoustic waves or completely absorbed, thereby avoiding the problem of these cavity frequencies resonating with LP compressor / LP compressor component energy outside the VBV cavity. In some examples, the ABH assembly includes a plurality of plates (e.g., fins, baffles, etc.) coupled to the inner wall of the housing to vibrate based on the acoustic resonance of the VBV cavity. In some examples, the plates have a surface area and / or size that varies along the depth of the VBV cavity (e.g., the plate size increases in a radially outward direction). The oscillation of the plates drives acoustic waves into the ABH cavity and converts the acoustic energy into mechanical and thermal energy that is subsequently dissipated. As a result, acoustic / aerodynamic feedback energy is completely or significantly reduced.

[0036] As used herein, "acoustic black hole" refers to a system, device and / or component for passively controlling the acoustic response or vibration in a cavity. In some examples, local inhomogeneities are embedded in a thin-walled structure (such as a disk, fin, beam or plate) to construct an ABH. In some examples, the thin-walled structure is positioned within the body of the ABH (such as a cylinder with an open top). The inhomogeneity can be a change in the geometry or material properties of the thin-walled structure according to a spatial power law distribution. In addition, the thin-walled structure can include one or more layers of viscoelastic material. Such a thin-walled structure provides attenuation properties for the ABH. In other words, the ABH reduces the speed of elastic waves (such as sound waves) propagating within the ABH. When the thickness of the thin-walled structure decreases to zero at the center of the ABH, the wave speed decreases to zero. When the ABH has a non-zero residual thickness at its center, the wave speed decreases but does not disappear. Therefore, in some examples, the ABH (such as a thin-walled structure, etc.) is combined with a lossy medium (such as a viscoelastic layer) to improve the structural loss factor. In other words, the ABH acts as a wave trap, extracting and dissipating vibrational energy from the host medium (e.g., air) without releasing or reflecting the energy.

[0037] The example VBV assemblies disclosed herein dampen the acoustic response of air within the VBV cavity, thereby reducing oscillations of air within a supercharger / LP compressor when the VBV door is in the closed position. Thus, the disclosed examples enable the manufacture of VBV assemblies that reduce vibrations in an LP compressor or supercharger at various resonant frequencies of the VBV cavity. In other words, the example VBV assemblies disclosed herein reduce vibration damage to the rotor system of a supercharger / LP compressor.

[0038] Referring now to the drawings, wherein like numerals represent like elements throughout the several views, Figure 1 1 is a schematic cross-sectional view of an example high-bypass turbofan gas turbine engine 110 ("turbofan engine 110"). Although the example shown is a high-bypass turbofan engine, the principles of the present disclosure are also applicable to other types of engines, such as low-bypass turbofan engines, turbojet engines, turboprop engines, etc. Figure 1 As shown, turbofan engine 110 defines a longitudinal or axial centerline axis 112 extending therethrough for reference. Figure 1 Also included are annotated directional diagrams that reference an axial direction A, a radial direction R, and a circumferential direction C. Generally speaking, as used herein, the axial direction A is a direction extending generally parallel to the centerline axis 112 , the radial direction R is a direction extending orthogonally outward from the centerline axis 112 , and the circumferential direction C is a direction extending concentrically about the centerline axis 112 .

[0039] Generally speaking, turbofan engine 110 includes a core turbine or gas turbine engine 114 disposed downstream of a fan section 116. Core turbine 114 includes a substantially tubular outer casing 118 defining an annular inlet 120. Outer casing 118 may be formed from a single casing or multiple casings. Outer casing 118 surrounds, in series flow relationship, a compressor section having a booster or low-pressure compressor 122 ("LP compressor 122") and a high-pressure compressor 124 ("HP compressor 124"); a combustion section 126; a turbine section having a high-pressure turbine 128 ("HP turbine 128") and a low-pressure turbine 130 ("LP turbine 130"); and an exhaust section 132. A high-pressure shaft or spool 134 ("HP shaft 134") drivingly couples HP turbine 128 and HP compressor 124. A low-pressure shaft or spool 136 ("LP shaft 136") drivingly couples LP turbine 130 and LP compressor 122. The LP shaft 136 can also be coupled to a fan spool or fan shaft 138 of the fan section 116. In some examples, the LP shaft 136 is directly coupled to the fan shaft 138 (e.g., a direct drive configuration). In an alternative configuration, the LP shaft 136 can be coupled to the fan shaft 138 via a reduction gear 139 (e.g., an indirect drive or gear drive configuration).

[0040] like Figure 1 As shown, fan section 116 includes a plurality of fan blades 140 coupled to and extending radially outward from fan shaft 138. An annular fan casing or nacelle 142 circumferentially surrounds fan section 116 and / or at least a portion of core turbine 114. Nacelle 142 may be supported relative to core turbine 114 by a plurality of circumferentially spaced outlet guide vanes 144. Furthermore, a downstream section 146 of nacelle 142 may surround the exterior of core turbine 114 to define a bypass airflow passage 148 therebetween.

[0041] like Figure 1 As shown, air 150 enters an inlet portion 152 of the turbofan engine 110 during operation. A first portion 154 of the air 150 flows into the bypass airflow passage 148, while a second portion 156 of the air 150 flows into the inlet 120 of the LP compressor 122. One or more successive stages of LP compressor stator blades 170 and LP compressor rotor blades 172 coupled to the LP shaft 136 progressively compress the second portion 156 of the air 150 flowing through the LP compressor 122 and toward the HP compressor 124. Next, one or more successive stages of HP compressor stator blades 174 and HP compressor rotor blades 176 coupled to the HP shaft 134 further compress the second portion 156 of the air 150 flowing through the HP compressor 124. This provides the compressed air 158 to the combustion section 126, where it is mixed with fuel and combusted to provide combustion gases 160.

[0042] Combustion gases 160 flow through the HP turbine 128, where one or more successive stages of HP turbine stator blades 166 and HP turbine rotor blades 168 coupled to the HP shaft 134 extract a first portion of kinetic and / or thermal energy from the combustion gases. This energy extraction supports the operation of the HP compressor 124. Combustion gases 160 then flow through the LP turbine 130, where one or more successive stages of LP turbine stator blades 162 and LP turbine rotor blades 16 coupled to the LP shaft 136 extract a second portion of thermal and / or kinetic energy from the combustion gases. This energy extraction rotates the LP shaft 136, thereby supporting the operation of the LP compressor 122 and / or the rotation of the fan shaft 138. Combustion gases 160 then exit the core turbine 114 through its exhaust section 132. A turbine frame 161 with a cowling assembly is located between the HP turbine 128 and the LP turbine 130. Turbine frame 161 serves as a support structure, connecting the aft bearing of the high-pressure shaft to the turbine casing and forming an aerodynamic transition duct between the HP turbine 128 and the LP turbine 130. The fairing forms a flow path between the high-pressure and low-pressure turbines and may be formed using metal castings (eg, nickel-based cast metal alloys, etc.).

[0043] Core turbine 114 is used for similar purposes as turbofan engine 110 and is exposed to similar environments as land-based gas turbines, turbojet engines (where the ratio of first portion 154 of air 150 to second portion 156 of air 150 is less than that of a turbofan engine), and unducted fan engines (where fan section 116 lacks nacelle 142). In turbofan engines, turbojet engines, and unducted fan engines, a reduction gear (e.g., reduction gear 139) may be included between any shaft and spool. For example, reduction gear 139 is provided between LP shaft 136 and fan shaft 138 of fan section 116.

[0044] As mentioned above about Figure 1 As described above, the turbine frame 161 is located between the HP turbine 128 and the LP turbine 130 to connect the rear bearing of the high-pressure shaft to the turbine housing and to form an aerodynamic transition duct between the HP turbine 128 and the LP turbine 130. In this way, air flows through the turbine frame 161 between the HP turbine 128 and the LP turbine 130.

[0045] Figure 2 is a turbine engine (e.g. Figure 1 A partial cross-sectional view of an example compressor 200 of a turbofan engine 110 of FIG. 1 includes an example LP compressor or supercharger section 202 and an example HP compressor section 204. The supercharger section 202 and the HP compressor section 204 may correspond to Figure 1LP compressor 122 and HP compressor 124 of turbofan engine 110 . Figure 2 An example compressor 200 is shown at a transition point 206 between a supercharger section 202 and an HP compressor section 204. The compressor 200 includes an example housing 208. Figure 2 In the illustrated example of FIG, a supercharger housing 208a surrounds the supercharger section 202 and the HP compressor section 204. In some examples, the supercharger section 202 and the HP compressor section 204 have different housings 208 connected via a linkage. Figure 2 As shown, the housing 208 has a first housing (referred to herein as the supercharger housing 208a) and a second housing 208b (referred to herein as the compressor housing 208b). The housing 208 surrounds the rotor blades 210a and stator vanes 210b of the compressor 200. In operation, the rotor blades 210a rotate, thereby forcing air to flow downstream. The stator vanes 210b redirect the airflow and reduce its velocity, thereby increasing downstream pressure. The housing 208 defines an example main flow path 212 (e.g., a first flow path) for airflow through the compressor 200 (e.g., and the turbofan engine 110).

[0046] As an example Figure 2 As shown, the VBV assembly 213 of the gas turbine engine 114 includes a VBV port 214 (e.g., a passage, opening, duct, etc.) to divert air from the primary flow path 212 and bypass the HP compressor section 204. The VBV port 214 defines an example exhaust flow path 216 (e.g., a secondary flow path) between the supercharger section 202 and the VBV port outlet 218. More specifically, the VBV port 214 includes a forward VBV wall 220a and a rearward VBV wall 220b extending radially outward between the supercharger section 202 and the VBV port outlet 218. In some examples, the forward VBV wall 220a and the rearward VBV wall 220b define an annular geometry of the VBV port 214.

[0047] exist Figure 2 In the example shown, the VBV assembly 213 includes a VBV door 222 to restrict or allow airflow through the exhaust flow path 216. The VBV assembly 213 includes a VBV actuation system 224 to actuate the VBV door 222 between an open position 226 and a closed position. For example, the VBV actuation system 224 may include one or more levers (e.g., rocker arms, etc.), linkages, and / or other actuation devices to slide the VBV door 222 between the open position 226 and the closed position. Thus, the VBV door 222 is actuable (e.g., movable, translatable, rotatable, etc.) between the open position 226 and the closed position.

[0048] exist Figure 2In the example shown, a VBV door 222 and a VBV actuation system 224 are located near the VBV port outlet 218. The VBV actuation system 224 moves the VBV door 222 (e.g., a blocking door, etc.) into a closed position to cover the VBV port outlet 218. When the VBV door 222 is in the closed position, the exhaust flow path 216 is blocked, and air in the VBV port 214 becomes relatively stagnant compared to the main flow path 212. In some examples, when the VBV door 222 is in the closed position, the VBV door 222, the front VBV wall 220a, and the rear VBV wall 220b of the VBV port 214 define an example VBV cavity 228 (also referred to as an exhaust cavity). As a result, a shear layer of airflow separates from the cavity inlet at the front VBV wall 220a and strikes the edge of the rear VBV wall 220b, generating acoustic feedback. The feedback resonates with the VBV cavity 228, and a high-energy acoustic tone emanates from the VBV cavity 228. This acoustic tone extends across the inlet 230 to the VBV port 214, substantially trapping the air pocket within the VBV cavity 228. The air flow along the main flow path 212 and the shear layer oscillates and causes the air within the VBV cavity 228 to resonate at various frequencies. This acoustic resonance of the VBV cavity 228 can lead to acoustic excitation in the supercharger section 202 and compressor hardware. Advantageously, the example VBV assembly disclosed herein includes an acoustic black hole to dampen the acoustic resonance of the VBV cavity 228.

[0049] Figure 3A yes Figure 2 A side view of an example compressor 200 including a first variable exhaust valve (VBV) assembly 213 is shown, which may be applied to a turbine engine (e.g., Figure 1 and / or turbofan engine 110 in 2). Figure 3B It is intercepted along line AA Figure 3A A cross-sectional front view of an example compressor 200 is shown in FIG. Figure 3A and 3B In the illustrated example, the VBV door 222 is in the open position 226. Figure 3B Not visible in.

[0050] exist Figure 3A and 3BIn the example shown, the supercharger housing 208a surrounds the supercharger section 202 of the compressor 200, while the compressor housing 208b surrounds the HP compressor section 204 of the compressor 200. The supercharger housing 208a is coupled to the compressor housing 208b at a transition point 206. The VBV assembly 213 includes one or more VBV ports 214 integrated into the housing 208 to exhaust air from the main flow path 212. In some examples, the VBV ports 214 are formed at the transition point 206 between the supercharger housing and the compressor housings 208a, 208b. For example, the supercharger housing 208a may include a front VBV wall 220a ( Figure 2 ), while the compressor housing 208b may include a rear VBV wall 220b ( Figure 2 ). Thus, the VBV port 214 can be created based on the coupling of the housings 208a, 208b. In some examples, the VBV port 214 is machined into the housing 208. In some examples, an additive manufacturing process integrates the VBV port 214 into the housing 208. Additionally or alternatively, the VBV port 214 can be manufactured separately and coupled (e.g., welded, bolted, etc.) to the housing 208.

[0051] In some examples, the VBV assembly 213 selectively discharges air based on the number of VBV ports 214. For example, the housing 208 may include 8 to 18 VBV ports 214 based on a target discharge flow rate. In some examples, respective ones of the VBV ports 214 include doors that can be actuated between open and closed positions to adjust the discharge flow rate of the VBV assembly 213 based on the target discharge flow rate and / or flight conditions of the aircraft. In some examples, the VBV assembly 213 includes a single, unified VBV port 214 that is centered about the longitudinal axis (e.g., Figure 1 The centerline axis 112) extends continuously circumferentially. Figure 3A and 3B In the example shown, the VBV assembly 213 includes a plurality of baffles 300 (e.g., struts, ribs, support beams, etc.) to define the VBV ports 214. That is, the baffles 300 circumferentially separate and define adjacent ones of the VBV ports 214. The plurality of baffles 300 are circumferentially spaced about the compressor 200 at substantially similar axial and radial positions.

[0052] exist Figure 3B In the example shown, the supercharger housing 208a and the compressor housing 208b include an example exterior surface 302 and an example interior surface 304. Figure 3B In the example, Figure 3BDimension 306 corresponds to the thickness of the casings 208a, 208b and / or the radial length of the VBV port 214. For example, the compressor casing 208b extends radially outward from the inner surface 304 to the outer surface 302 by dimension 306. In some examples, the VBV port 214 extends radially beyond the outer surface 302 and has a radial length greater than dimension 306.

[0053] exist Figure 3B In the example shown, each VBV port 214 includes Figure 2 2. In some examples, the VBV ports 214 have similar dimensions, and the VBV cavities 228 have similar volumes. Alternatively, some of the VBV ports 214 may have varying dimensions, and some of the VBV cavities 228 may have varying volumes based on the respective positions of the diaphragms 300. However, in some examples, the VBV assembly 213 includes a single (e.g., unified, continuous, etc.) VBV port 214, such that the VBV cavity 228 extends circumferentially around the longitudinal axis of the compressor 200.

[0054] Various example VBV components according to the teachings of the present disclosure are described in further detail below. Figure 2 、 3A and 3B . Thus, the examples disclosed below include an example housing 208 (e.g., a booster housing 208a and a compressor housing 208b) defining a primary flow path 212, and an example VBV port 214 defining an example exhaust flow path 216. However, it should be understood that the examples disclosed herein may be implemented in one or more compressors, such as a high-pressure compressor, a low-pressure compressor, etc. Furthermore, the examples disclosed herein may be implemented on compressors having various configurations, such as including one or more VBV ports, compressor stages, etc. Furthermore, the examples disclosed herein may be applied to various turbine engines, such as multi-spool turbine engines, turboshaft engines, turbine engines having one compressor section, etc. The examples disclosed below may include a controller to determine actuation of the VBV assembly disclosed herein.

[0055] Figure 2 、 3A The VBV port 214 of the VBV assembly 213 in FIG3B can resonate at an acoustic frequency based on the volume of the VBV cavity 228. That is, when the VBV door 222 is in the closed position and air flows through the inlet 230 ( Figure 2 )hour, Figure 2The VBV port 214 in the compressor 200 resonates at an acoustic frequency, also referred to herein as a resonant frequency. Thus, the VBV assembly 213 can generate air wave oscillations in the supercharger section 202 of the compressor 200, thereby exciting mechanical components of the supercharger section 202 (e.g., rotor blades 210a, stator vanes 210b, etc.).

[0056] Figure 4A yes Figure 2 FIG. 1 is a partial cross-sectional side view of an example compressor 200 including an example first VBV assembly 400a according to the teachings disclosed herein. Figure 4B yes Figure 2 FIG. 1 is a partial cross-sectional side view of an example compressor 200 including an example second VBV assembly 400 b according to the teachings disclosed herein. Figure 4A The first VBV component 400a and Figure 4B Many components of the second VBV assembly 400b are combined with the above Figure 2 、 3A 3B VBV assembly 213 are substantially similar or identical to the components described. Therefore, these components will not be described in detail. Instead, the interested reader is referred to the corresponding description above for a complete written description of the structure and operation of these components. To facilitate this process, Figure 4A and 4B The general will use Figure 2 、 3A Similar or identical reference numbers as in 3B are used to denote similar structures. With respect to the figures disclosed herein, like numbers denote like elements throughout the figures.

[0057] Figure 4A The first VBV assembly 400a includes a first acoustic black hole (ABH) assembly 402a coupled to a door 404 . Figure 4B The second VBV assembly 400b includes a second ABH assembly 402b coupled to a door 404. Figure 4A and 4B In the illustrated example, the first ABH assembly 402a and the second ABH assembly 402b include similar and / or identical elements. Figure 4A The description related to the first ABH component 402a may apply to Figure 4B Similar elements of the second ABH assembly 402b have the same reference numbers. Furthermore, the first ABH assembly 402a and the second ABH assembly 402b have similar functions and / or advantages. Therefore, unless otherwise noted, the description of the operation of the first ABH assembly 402a is also applicable to the second ABH assembly 402b.

[0058] exist Figure 4A and 4B, the door 404 is in the closed position 406. In some examples, the door 404 can be actuated via an actuation system (e.g., Figure 2 The VBV actuation system 224 in the embodiment of the present invention is actuated in a forward direction 408. Thus, the door 404 can be moved between a closed position 406 and an open position (e.g., a fully forward position). When the door 404 is in the closed position 406, the first ABH assembly 402a absorbs the resonant acoustic waves generated in the VBV port 214.

[0059] The first ABH assembly 402a of the illustrated example includes a body 410 defining an ABH cavity 412. More specifically, the body 410 includes a front interior surface 414, a rear interior surface 416, and a radially outer surface 418 (e.g., a ceiling) that form a rectangular cross-sectional profile of the ABH cavity 412. In some examples, the radially outer surface 418 is curved to form a domed cover for the body 410. In some examples, the body 410 includes a single curved inner wall that forms the domed cross-sectional profile of the ABH cavity 412. In some examples, the door 404 includes one or more openings 420 (e.g., orifices, holes, slots, etc.) to allow airflow into and out of the ABH cavity 412.

[0060] In the example shown, the first ABH assembly 402a is an annular ABH assembly that surrounds a gas turbine engine (eg, Figure 1 10 . The body 410 may extend circumferentially about a longitudinal axis (e.g., centerline axis 112) of the turbofan engine 110 in FIG. 10 . Thus, the body 410 may extend circumferentially about the longitudinal axis. Furthermore, the front interior surface 414 and the rear interior surface 416 are discrete walls such that the front interior surface 414 and the rear interior surface 416 are separated by a first dimension 422. For example, the first dimension 422 corresponds to the inner width of the body 410. In some examples, the front interior surface 414 and the rear interior surface 416 are substantially parallel (e.g., within + / - 10%, etc.). In some examples, the front interior surface 414 and the rear interior surface 416 are inclined such that the first dimension 422 is variable along a second dimension 424 (e.g., depth) of the body 410.

[0061] In some examples, the first ABH assembly 402a is an ABH plug assembly rather than an annular assembly. For example, the body 410 can be an axisymmetric cylinder aligned with the radial axis of the gas turbine engine. Thus, the front interior surface 414 can correspond to a single uniform inner wall of the cylindrical structure. When the example first ABH assembly 402a corresponds to an ABH plug assembly, the first dimension 422 is the inner diameter of the body 410. Figure 5A 、 5B , 6, and 7 provide further details describing example ring, plug, and / or other configurations of the first ABH assembly 402a.

[0062] Figure 4A The first ABH assembly 402a of the illustrated example includes a first plurality of plates 425a (which may also be referred to as fins or baffles) for directing acoustic waves into the ABH cavity 412. Furthermore, the first plates 425a dissipate acoustic energy generated in the VBV port 214. This acoustic energy may correspond to air pressure fluctuations that propagate from the VBV cavity 228 and oscillate at the resonant frequency of the VBV port 214.

[0063] exist Figure 4A In the illustrated example, a first set of first plates 425a is coupled to the front interior surface 414 of the body 410, while a second set of first plates 425a is coupled to the rear interior surface 416 of the body 410. Thus, the first plates 425a extend circumferentially along the annular shape of the body 410 and the front and rear interior surfaces 414, 416. Furthermore, the first plates 425a extend axially outward from the front and rear interior surfaces 414, 416 and into the ABH cavity 412. For example, the first plates 425a are rings surrounding the door 404 and protrude inwardly (e.g., toward the transverse axis 426) from the front and rear interior surfaces 414, 416 of the body 410. In some examples, the plates 425a have a tapered or wedge-shaped profile. That is, the thickness of the plates 425a may decrease along the span of the plates 425a. For example, the thickness profile of the plates 425a may decrease from the base (e.g., at the front interior surface 414) to the tip. In some examples, the thickness of plate 425a decreases from the root to the tip according to a power law relationship of thickness as a function of distance from the root. Examples of these thickness variations are described herein. Figures 12A-12D Further details disclosed.

[0064] exist Figure 4A In the example shown, each first plate 425a has a surface area (viewed in a radially outward direction 428), and the first plates 425a are arranged such that the surface area of ​​the plates 425a varies (e.g., increases or decreases) along the depth in the radially outward direction 428. In other words, the plates 425a are positioned along the second dimension 424 (e.g., depth) within the gas turbine engine 114 ( Figure 1 ) has a variable surface area in the radially outward direction 428. In the example shown, the first plate 425a is arranged so that the surface area of ​​the first plate 425a increases in the radially outward direction 428 along the transverse axis 426. Figure 4A The first plate 425a is a cantilevered ring whose span (eg, axial length) increases along the transverse axis 426 and in a radially outward direction 428 .

[0065] exist Figure 4BIn the example shown, the second ABH assembly 402b includes a second plurality of plates 425b having a variable size in a radially outward direction 428 along a second dimension 424 (e.g., depth) of the body 410. In the example shown, the second plates 425b are disposed in the center of the ABH cavity 412 and increase in size in the radially outward direction 428 along a transverse axis 426. In some examples, the second plates 425b are coupled to posts 427 extending from the radially outer surface 418. Figure 4A Similar to the configuration in , the open area in the ABH cavity 412 decreases in the radially outward direction as the size of the plate increases.

[0066] Figure 4A The first ABH assembly 402a in FIG. 4 includes a first portion of a first plate 425a coupled to the front interior surface 414 and a second portion of the first plate 425a coupled to the rear interior surface 416. In the example shown, some of the first set of first plates 425a are aligned with corresponding ones of the second set of first plates 425a. In some examples, the first set of first plates 425a and the second set of first plates 425a are misaligned or offset in the axial direction.

[0067] The first plurality of plates 425a within the ABH cavity 412 vibrates based on the acoustic resonance of the VBV cavity 228. The vibrating first plates 425a drive or guide incident (e.g., incoming) sound waves into the ABH cavity 412 to strike the radially outer surface 418. After the sound waves strike the radially outer surface 418 and / or the front and rear interior surfaces 414 and 416, the pressure oscillations reflect from the interior surfaces 414-418 and reverberate within the body 410. The reflected and reverberating sound waves cause the first plates 425a to oscillate or vibrate, thereby converting the sound energy into heat (e.g., heat in the air and / or within the plates 425a). As the sound energy dissipates, the amplitude and / or frequency of the sound waves also dissipate. As a result, the sound waves are either reflected back into the ABH cavity 412 at a reduced frequency (e.g., energy) or absorbed within the body 410. In some examples, the first plate 425 a attenuates incident sound waves to an extent such that the resonant tones become quieter before or upon reaching the radially outer surface 418 .

[0068] In some examples, the radially outer surface 418 includes a damping material to provide additional sound absorption to the first ABH assembly 402a. For example, the radially outer surface 418 can be lined with foam, vinyl, polytetrafluoroethylene (Teflon), adhesive, or another material including viscoelastic and acoustic damping materials. Examples of damping materials will be combined with Figure 8CFurther details are disclosed. In addition, the first plate 425a and the second plate 425b can include a damping material to increase the sound absorption ability of the first ABH assembly 402a and / or the second ABH assembly 402b. For example, the first plate 425a can include a damping material (e.g., foam, Teflon, rubber, etc.) coupled to the base or root of each first plate 425a. In some examples, a layer of damping material is coupled to the length of the first plate 425a on one or both sides. Figure 12B Examples of damping materials are disclosed in further detail.

[0069] Figure 5A is a cross-sectional front view of an example third VBV assembly 500a including a third ABH assembly 502a. Figure 5B is a cross-sectional front view of an example fourth VBV assembly 500b including a fourth ABH assembly 502b. In some examples, the third VBV assembly 500a and / or the fourth VBV assembly 500b implement Figure 4A The first VBV assembly 400a and / or Figure 4B Furthermore, in some examples, the third ABH component 502a and / or the fourth ABH component 502b implement Figure 4A The first ABH component 402a and / or Figure 4B The second VBV component 400b. Therefore, Figure 5A The third VBV component 500a and Figure 5B The fourth VBV component 500b may include Figure 4A or the first or second ABH assembly 402a, 402b in 4B. Figure 5A and 5B The cross-sectional front view of the third VBV assembly 500a and the fourth VBV assembly 500b shown in FIG is taken along Figure 4A Unless otherwise stated, the Figure 5A The description of the third VBV component 500a also applies to Figure 5B The fourth VBV component 500b in.

[0070] The third VBV assembly 500a includes a third ABH assembly 502a for absorbing sound waves that resonate radially outward from the VBV cavity 228. Figure 5A In the example shown, the third ABH component 502a includes Figure 4A and / or body 410 of 4B, which extends circumferentially around the longitudinal axis 504 of the compressor 200. Figure 5A In the example of FIG. 4 , the body 410 is an annular structure that defines an ABH cavity 412 ( Figure 4A and / or 4B), which surrounds the VBV cavity 228. In some examples, the longitudinal axis 502 corresponds to Figure 1 In some examples, the second dimension 424 (eg, height) of the ABH cavity 412 is along the centerline axis 112 of the door 404 ( Figure 4A and / or 4B) the circumference is constant (eg, constant within + / - 10%).

[0071] Figure 5A The third ABH assembly 502a may include a Figure 4A Thus, the first plates 425a can extend circumferentially around the longitudinal axis 502. The first plates 425a have an annular shape and a variable diameter such that adjacent ones of the first plates 425a surround each other in a nested configuration.

[0072] exist Figure 5B In the example shown, the fourth ABH assembly 502b includes a plurality of baffles 506 coupled to the door 404 and an interior surface 508 (eg, Figure 4A and 4B 418). Additionally, in some examples, a plurality of baffles 506 are coupled to the Figure 4A and 4B The front inner surface 414 and the rear inner surface 416 of the fourth ABH assembly 502b thus include Figure 5B 506 to define a plurality of ABH cavities 510. Furthermore, in the example shown, some of the baffles 506 are circumferentially spaced apart at angles 512 (e.g., approximately 45 degrees, approximately 30 degrees, approximately 60 degrees, etc.). More specifically, the first baffle 506a is radially and axially aligned with a first transverse axis 514, the second baffle 506b is radially and axially aligned with a second transverse axis 516, and the third baffle 506c is radially and axially aligned with a third transverse axis 518. The transverse axes 514-518 intersect and intersect with the longitudinal axis 504 (e.g., Figure 1 The second transverse axis 516 is oriented at an angle 512 relative to the first transverse axis 514. Similarly, the third transverse axis 518 is oriented at an angle 512 relative to the second transverse axis 516.

[0073] In some examples, corresponding ones of the plurality of baffles 506 are circumferentially spaced apart at an angle 512. Thus, the angle 512 can be based on the number of baffles 506 included in the fourth ABH assembly 502b (e.g., eight baffles 506 correspond to 45 degrees of the angle 512). Furthermore, the volume of the ABH cavity 510 is based on the angle 512 and the circumferential distance between adjacent ones of the baffles 506. For example, the first baffle 506a and the second baffle 506b define a first ABH cavity 510a, while the second baffle 506b and the third baffle 506c define a second ABH cavity 510b. In some examples, the first ABH cavity 510a and the second ABH cavity 510b have the same volume. Alternatively, the first ABH cavity 510a and the second ABH cavity 510b can have different volumes. In some examples, the first portion of the ABH cavity 510 has a first volume, and the second portion of the ABH cavity 510 has a second volume different from the first volume.

[0074] Figure 6 is a cross-sectional front view of an example fifth VBV assembly 600 including an example fifth ABH assembly 602 according to the teachings disclosed herein. In some examples, the fifth ABH assembly 602 implements Figure 4A The first ABH component 402a or Figure 4B The cross-sectional front view of the fifth VBV assembly 600 is taken along the first transverse axis 604. In some examples, Figure 6 The first horizontal axis 604 corresponds to Figure 4A and 4B The horizontal axis is 426.

[0075] exist Figure 6 In the example shown, the fifth ABH assembly 602 is an ABH plug assembly including a plurality of ABH plug bodies 606. The ABH plug bodies 606 are connected to the ABH plug body 606. Figure 1 The plurality of ABH plug bodies 606 include a first ABH plug body 606a aligned with the first transverse axis 604. In some examples, the first ABH plug body 606a is aligned with the radial or transverse axis of the gas turbine engine 114 and / or compressor 200. Figure 4A and / or the body 410 of 4B.

[0076] The first ABH plug body 606a may be a cylindrical body centered about the first transverse axis 604. For example, Figure 6 The first ABH plug body 606a in FIG. 1 is an open-topped cylinder having an interior surface or wall 608 extending circumferentially around the first transverse axis 604. Additionally, the first ABH plug body 606a can define an inner diameter 609. In some examples, the inner diameter 609 corresponds to Figure 4A and 4BOptionally, the first ABH plug body 606a is non-cylindrical and includes an oval, rectangular, or triangular shape (eg, a cross-sectional profile).

[0077] In the illustrated example, the first ABH plug body 606a is similar or identical to the other plug bodies in the plurality of ABH plug bodies 606. However, some of the ABH plug bodies 606 may have variable dimensions (e.g., internal volume) and / or shapes to adjust the range of resonant frequencies that the fifth ABH assembly 602 can attenuate. For example, the fifth ABH assembly 602 may include a first ABH plug body 606a defining a first ABH cavity 610a and a second ABH plug body 606b defining a second ABH cavity 610b. Furthermore, the first ABH cavity 610a may have a first volume, while the second ABH cavity 610b may have a second volume different from the first volume. Thus, in some examples, when the internal volume of the first ABH plug body 606a is greater than the internal volume of the second ABH plug body 606b, the first ABH plug body 606a may suppress a first resonant frequency (e.g., 200 Hz), while the second ABH plug body 606b may suppress a second resonant frequency (e.g., 400 Hz) that is greater than the first frequency. In some examples, the first portion of the ABH plug body 606 has a volume of a first ABH cavity 610 a, while the second portion of the ABH plug body 606 has a volume of a second ABH cavity 610 b. In other words, the first portion of the ABH plug body 606 can reduce a first frequency, while the second portion of the ABH plug body 606 can reduce a second frequency different from the first frequency.

[0078] Furthermore, in the example shown, some of the ABH plug bodies 606 are circumferentially spaced apart at angles 610 (e.g., 45 degrees, 30 degrees, 60 degrees, etc.). More specifically, the second ABH plug body 606 b is radially and axially aligned with a second transverse axis 612 that is aligned with the first transverse axis 604 and a longitudinal axis 614 of the compressor 200 (e.g., Figure 1 The second transverse axis 612 intersects the first transverse axis 604. The second transverse axis 612 is oriented at an angle 610 relative to the first transverse axis 604. In some examples, corresponding ones of the plurality of ABH plug bodies 606 are circumferentially spaced apart at the angle 610. Thus, the angle 610 can be based on the number of ABH plug bodies 606 included in the fifth ABH assembly 602 (e.g., eight ABH plug bodies 606 correspond to 45 degrees of the angle 610). Alternatively, the plurality of ABH plug bodies 606 can be circumferentially spaced apart at varying angles.

[0079] exist Figure 6In the illustrated example, multiple ABH plug bodies 606 are coupled to a door 616 of a third ABH assembly 602. For example, the ABH plug bodies 606 can be fastened (e.g., bolted, welded, brazed, etc.) to an outer surface 618 of the door 616. Additionally or alternatively, one or more ABH plug bodies 606 can be integrated into the door 616 (e.g., by casting, molding, additive manufacturing, etc.). Furthermore, the door 616 includes multiple apertures 620 adjacent to the multiple ABH plug bodies 606. For example, the door 616 includes first apertures 620a adjacent to the first ABH plug body 606a to allow oscillating air pressure (e.g., sound waves) to enter the first ABH cavity 610a. In some examples, the size of the apertures 620 corresponds to the inner diameter 609 of the ABH plug body 606. Furthermore, the shape of the apertures 620 can correspond to the cross-sectional shape of the ABH plug body 606.

[0080] The plurality of ABH plug bodies 606 include a plurality of plates or disks (eg, branch disks) to dampen the acoustic resonance of the VBV cavity 228. In some examples, the ABH plug body 606 may include a plurality of plates or disks (eg, branch disks) to dampen the acoustic resonance of the VBV cavity 228. Figure 4A 4 or 4B. However, the first ABH plug body 606a includes a disk coupled to the interior surface 508 such that the disk extends circumferentially about the first transverse axis 604. Furthermore, the example plate / disk of the first ABH plug body 606a extends radially away from the interior surface 508 toward the first transverse axis 604. Thus, the plate of the first ABH plug body 606a includes an aperture that is aligned with (e.g., centered on) the first transverse axis 604. The orientation of the plate is substantially orthogonal (e.g., ±3°) to the first transverse axis 604. In some examples, the surface area of ​​the plate or disk along the first transverse axis 604 in the radially outward direction 428 ( Figure 4A ) increases in the radially outward direction 428 while the diameter of the orifice decreases. Conversely, in other examples, the surface area of ​​the plate or disk may decrease in the radially outward direction 428 along the first transverse axis 604 while the diameter of the orifice increases. In such examples, the first ABH plug body 606a may include a radially outer surface (e.g., Figure 4A and 4B The cone is connected to the radial outer surface 418).

[0081] Figure 7 is a cross-sectional front view of an example sixth VBV assembly 700 including an example sixth ABH assembly 702 according to the teachings disclosed herein. In some examples, the sixth ABH assembly 702 implements Figure 4A The first ABH component 402a or Figure 4B The cross-sectional front view of the sixth VBV assembly 700 is taken along the first transverse axis 604. In some examples, Figure 7The first horizontal axis 704 corresponds to Figure 4A and 4B The horizontal axis is 426.

[0082] exist Figure 7 In the example shown, the sixth ABH assembly 702 includes a first ABH cavity 706 , a second ABH cavity 708 , a third ABH cavity 710 , and a fourth ABH cavity 712 . Figure 7 The ABH cavities 706-712 can be additively manufactured to the door 714 (e.g., Figure 4A 4 ) on the door 404, thereby providing different volumes for each of the ABH cavities 706-712. For example, the first ABH cavity 706 can be smaller than the second ABH cavity 708, the second ABH cavity 708 can be smaller than the third ABH cavity 710, and the third ABH cavity 710 can be smaller than the fourth ABH cavity 712. The resonant frequencies that the ABH body can attenuate are based on the volumes of the cavities defined by the body. Therefore, the sixth ABH assembly 702 can attenuate four different resonant frequencies based on the four different volumes of the ABH cavities 706-712. For example, the first ABH cavity 706 can attenuate an 800 Hz resonant frequency, the second ABH cavity 708 can attenuate a 600 Hz resonant frequency, the third ABH cavity 710 can attenuate a 400 Hz resonant frequency, and the fourth ABH cavity 712 can attenuate a 200 Hz resonant frequency.

[0083] Figures 8A-8J are cross-sectional views of various example ABH assembly designs that may be implemented in any of the example VBV assemblies disclosed herein. Figures 8A-8J Any of the example features of the ABH components may be combined or rearranged.

[0084] Figure 8A An example ABH assembly 800 is shown, which includes a body 802 defining a cavity 804 and a plurality of plates 806 in the cavity 804 (one of which is in the Figure 8A ). The body 802 has an end wall 808 and a side wall 810 that define a cavity 804. The side wall 810 defines an inlet 812 into the cavity 804. The ABH assembly 800 may include any number of plates, including a first plate 806a closest to the inlet 812 and a final plate 806n closest to the end wall 808. The ABH assembly 800 has a longitudinal or central axis 814. The axis 814 may correspond to a radial direction ( Figure 1 ).

[0085] exist Figure 8AIn the example shown, the plate 806 is coupled to the inner surface of the side wall 810 of the body 802 and extends inwardly therefrom. In some examples, the side wall 810 and the plate 806 are constructed as a one-piece component (e.g., a unitary structure). In other examples, the plate 806 can be a separate component coupled to the side wall 810, such as via welding, brazing, threaded fasteners, adhesives, etc. In some examples, the ABH assembly 800 is a separate plug assembly having a circular or cylindrical shape (e.g., as combined with Figure 6 In such an example, the plate 806 may be implemented with a central opening 816 aligned with the axis 814 (one of which is in the Figure 8A The diameter of the central opening 816 of the plate 806 decreases along the axis 814 from the inlet 812 toward the end wall 808. In other words, the central opening 816 in the plate 806 gradually decreases from the first plate 806a to the last plate 806n. This causes the flow path entering the ABH assembly 800 to gradually become thinner or conical. Figure 8A In the example shown, the ABH assembly 800 includes six plates 806. However, in other examples, the ABH assembly 800 can include more or fewer plates. In some examples, the plates 806 are spaced equidistant from one another. In other examples, the plates 806 can be spaced farther or closer from one another.

[0086] While the example ABH assembly 800 is described as having a circular or cylindrical plug assembly, in other examples, the ABH assembly 800 may be configured as a circumferential assembly extending circumferentially around the gas turbine engine 114, similar to a combination of a Figure 5A and 5B In such an example, sidewall 810 can be defined by two separate walls, including a first (front) wall (e.g., front interior surface 414) and a second (rear) wall (e.g., rear interior surface 416), and panel 806 can be divided into a pair of panels extending inwardly from the first and second walls.

[0087] Figure 8B ABH assembly 800 is shown with Figure 8A 806. In some examples, increasing the number of plates 806 results in attenuating feedback energy at a higher rate and capturing a wider frequency range.

[0088] Figure 8C An example of an ABH assembly 800 is shown having a damping material 818 (which may also be referred to as a mass absorber) in the space between the final plate 806n and the end wall 808. The damping material 818 may be composed of a material or materials having multiple channels, such as 1 / 4 wave honeycomb absorber, shape memory alloy (SMA), polytetrafluoroethylene (PTFE), steel wool. Damping material 818 helps to suppress or attenuate the remaining sound frequencies that are not suppressed / absorbed by plate 806.

[0089] Figure 8D Shows something like Figure 8C 800 and further includes a structural damping layer 820 between the damping material 818 and the end wall 808. In some examples, the structural damping layer 820 includes a viscoelastic or friction-based damper. The structural damping layer 820 further dissipates energy and reduces the transmission of acoustically induced vibrations to the mechanical structure.

[0090] Figure 8E An example is shown in which the ABH assembly 800 includes a perforated panel 822. The perforated panel 822 is disposed in the cavity 804 and extends along the inner peripheral edge of the plate 806. The perforated panel 822 can be constructed of any material capable of withstanding the temperatures and pressures in the compressor, such as metal (e.g., steel). The perforated panel 822 has a plurality of openings 824 (one of which is located at Figure 8E Some sound waves can pass through openings 824 and into the spaces between adjacent panels 806. When sound waves of the desired frequency resonate in these side cavities, the oscillatory motion of the air through the perforated panels 822 allows the sound energy to be converted and ultimately dissipated, further reducing the acoustic response of the cavity 804.

[0091] Figure 8F Shows something like Figure 8E The example ABH assembly 800 of the example in FIG. includes a perforated panel 822. However, in Figure 8F In the embodiment, the panels 806 are spaced apart in a non-linear arrangement. For example, the panels 806 near the inlet 812 are spaced farther apart from each other, while the panels 806 near the end wall 808 are spaced closer together. In some examples, this non-linear spacing helps to increase the effectiveness of the ABH assembly 800 in reducing and / or absorbing acoustics. In addition, in Figure 8F In the example of FIG. 8 , the ABH assembly 800 includes a damping material 818 in the space between the final plate 806 n and the end wall 808 .

[0092] Figure 8G Shown with Figure 8F The example of an ABH assembly 800 is similar and also includes a wire mesh sheet 826 along the perforated panel 822. The wire mesh sheet 826 helps to further suppress or attenuate airborne sound waves passing through the wire mesh sheet 826. In some examples, the ABH assembly 800 also includes a wire mesh absorber 828 located in the space between the final plate 806n and the end wall 808.

[0093] Figure 8H Shows something like Figure 8GThe ABH assembly 800 is an example of a ABH assembly 800 that further includes structural dampers 830 on one or more panels 806. These structural dampers 830 absorb at least a portion of the resonant energy and dissipate the energy as heat, thereby eliminating the VBV cavity resonance. The structural dampers 830 are used to dissipate the vibration energy as heat.

[0094] Figure 8I An example of an ABH assembly 800 is shown including an example perforated diaphragm 832. The perforated diaphragm 832 is similar to the perforated panel 822 ( Figures 8E-8H ), but extends through the side cavity between the plates 806. The perforated diaphragm 832 has a plurality of openings 834 (one of which is in the Figure 8I In some examples, such as Figure 8J As shown, ABH assembly 800 includes a perforated panel 822 and a perforated membrane 832. In some examples, openings 834 in perforated membrane 832 are smaller than openings 824 in perforated panel 822.

[0095] As described above, in some examples, the ABH assembly 800 is a plug-type assembly that can be symmetrical about the axis 814 ( Figure 8A ).For example, Figure 9 is a perspective cross-sectional view of an example ABH assembly 800. As shown, the body 802 is cylindrical. The plate 806 is disc-shaped. Figure 9 In the embodiment, the ABH assembly 800 includes Figure 8E Perforated panel 822 in.

[0096] In other examples, the ABH assembly may have a differently shaped profile. For example, Figure 10 An example of an ABH assembly 800 is shown in which the body 802 is a rectangular parallelepiped. For example, the body 802 can have a square or rectangular cross-section. In such an example, the plate 806 is also square or rectangular. In other examples, the ABH assembly 800 can have other shapes (e.g., conical).

[0097] Figures 11A-11E A further variation of the ABH assembly 800 is shown, which may be implemented in any of the example variable exhaust valves disclosed herein. Figures 11A-11E Any of the example features of the ABH components may be combined or rearranged.

[0098] Figure 11AAn example of an ABH assembly 800 is shown in which the outer diameter of the plates 806 varies. Specifically, the outer diameter of the plates 806 increases along the axis 814 from the inlet 812 toward the end wall 808. Consequently, the diameter of the sidewall 810 increases along the axis 814 from the inlet 812 toward the end wall 808. In the example shown, the inner diameter of the central opening 816 in the plates 806 is constant or the same across all plates 806.

[0099] Figure 11B Shown with Figure 11A Similar example of ABH assembly 800. However, in Figure 11B 816 , the inner diameter of the central opening 816 increases along the axis 814 from the inlet 812 toward the end wall 808 .

[0100] Figure 11C Shown with Figure 11A A similar example of ABH assembly 800 is shown, where plate 806 has a varying outer diameter and a constant inner diameter. Figure 11C , the ABH assembly 800 includes a perforated panel 822. In this example, the inner diameter of the plate 806 is constant, and thus the perforated panel 822 is cylindrical and / or has a constant diameter.

[0101] Figure 11D Shown with Figure 11B A similar example of ABH assembly 800 is shown, where plate 806 has a varying outer diameter and a varying inner diameter. Figure 11D , the ABH assembly 800 includes a perforated panel 822 .

[0102] Figure 11E Shown with Figure 11D A similar example of ABH assembly 800 is shown, except that in this example, the inner diameter of plate 806 decreases from inlet 812 to end wall 808 .

[0103] In some examples, the plate 806 of the ABH assembly 800 can be tuned (eg, via modulus and / or thickness) to structurally vibrate at a particular frequency of interest. For example, Figure 12A An example of an ABH assembly 800 is shown with plates 806 (one of which is in Figure 12A In some examples, the ABH assembly 800 can include damping material (e.g., foam, Teflon, rubber) on the plate 806 (e.g., on the top and bottom surfaces of the plate 806) to help dampen acoustic energy absorbed by the plate 806.

[0104] Figure 12B yes Figure 12A The enlarged view labeled 1200 in FIG. 1 shows the connection between the peripheral edge 1202 of the plate 806 and the side wall 810 of the body 802. In some examples, such as Figure 12B As shown, the plate 806 has a reduced or tapered thickness near the peripheral edge 1202. For example, the peripheral section 1204 of the plate 806 has a smaller thickness than the inner peripheral section 1206 of the plate 806. The reduced thickness at the attachment area provides the plate 806 with greater flexibility, thereby responding to higher frequencies than a plate with uniform thickness. This reduced thickness profile also provides an acoustic black hole absorption for vibration energy in the structure, thereby further suppressing the sound from the VBV. This enables the plate 806 to operate similar to a tuning fork, which is shaped and sized to vibrate a specific frequency or frequency band. This reduces the phase velocity, allowing the plate 806 more time to absorb energy. As Figure 12B As shown, the ABH assembly 800 can include a damping material 1208 (e.g., foam, Teflon, rubber) coupled to the plate 806 (e.g., applied to the top and bottom surfaces of the plate 806) along at least a portion of the peripheral section 1204. The damping material 1208 is used to attenuate or remove acoustic energy from the plate 806. Thus, the plate 806 is configured to attenuate or suppress acoustic vibrations of a particular frequency or frequency band. Other plates 806 can have the same reduced or tapered thickness or different reduced thicknesses to attenuate or suppress acoustic vibrations of different frequencies or frequency bands.

[0105] In some examples, plate 806 may be shaped to improve damping. For example, Figure 12C An example is shown in which the outer peripheral section 1204 of the plate 806 has a greater thickness than the inner peripheral section 1206. Furthermore, in this example, the outer peripheral section 1204 connected to the sidewall 810 is forked. In some examples, the forked connection provides a better path for transferring energy from the air to the sidewall 810. In some examples, the inner surface of the fork has a coating of a viscoelastic material.

[0106] Additionally or alternatively, the plate 806 can be manufactured with varying effective material density and / or elasticity to reduce phase velocity. For example, Figure 12D 806 is a cross-sectional view of plate 806 showing the internal material of plate 806. The material of plate 806 has a decreasing density from the inner peripheral edge to the outer peripheral edge (in the direction of the arrow), which reduces the effective phase velocity compared to a tapered thickness distribution, as an alternative method to provide an ABH effect of structure-borne energy. In some examples, plate 806 is constructed by additive manufacturing (e.g., 3D printing). Plate 806 can be constructed from internal structural members or via foam. As waves propagate through plate 806, the phase velocity of the waves decreases and approaches zero in the acoustic black hole.

[0107] In some examples, one or more plates 806 may be perforated plates having one or more openings (in addition to the central opening 816). Figure 13AAn example of an ABH assembly 800 is shown where a plurality of panels 806 have openings that allow acoustic airflow (as indicated by arrows) to flow in the direction of an axis 814 .

[0108] Figure 13B yes Figure 13A A top view of one of the plates 806 in FIG. Plate 806 has a central opening 816. Plate 806 also has a plurality of additional openings 1300 (one of which is in the Figure 13B ). Thus, plate 806 can be considered a perforated plate. In some examples, opening 1300 is smaller than central opening 816. Opening 1300 can be vibration tuned to receive acoustic energy from the air into plate 806 for additional damping.

[0109] In some examples, it is advantageous to maintain the same ratio of open area to enclosed area in each plate 806. In some examples, the open area ratio is calculated as a function of the disc fractional open area using the following formula:

[0110] πr′ 2 +σπ[R 2 -r′ 2 ]=πr 2 Equation 1.

[0111]

[0112] In Equations 1 and 2, r is the radius of the original central opening 816 (without perforations), R is the radius of the cavity 804, and r' is the new radius of the central opening 816. Porosity achieved through variable hole size and number of holes, as well as hole shape, allows designers to further adjust the acoustic resistance of air through the perforated plate, thereby providing damping to optimize ABH performance.

[0113] Figures 14A-14D An example of an ABH assembly 800 is shown that includes a chamber that helps further suppress or attenuate acoustic energy. Figures 14A-14D As shown, the body 802 includes chambers 1400, 1402, 1404 located outside (e.g., surrounding) the sidewall 810. The chambers 1400, 1402, 1404 can be cylindrical to match the shape of the sidewall 810. The sidewall 810 has openings 1406 (one of which is located at Figure 14A ), which extends in a radial direction relative to the axis 814. Acoustic waves from the cavity 804 can pass through the sidewalls 810 and into the chambers 1400, 1402, 1404, which helps to suppress the acoustic energy.

[0114] In some examples, the diameters of chambers 1400, 1402, 1404 vary. For example, Figure 14A and 14BIn the example of FIG. 8 , the diameters of the chambers 1400 , 1402 , 1404 increase from the inlet 812 toward the end wall 808 , while in FIG. Figure 14C and 14D 8, the diameters of the chambers 1400, 1402, 1404 decrease from the inlet 812 toward the end wall 808. The different diameters have the effect of attenuating or damping acoustic energy of different frequencies and / or frequency bands.

[0115] In some examples, the plate 806 may be coupled to only a portion or one side of the side wall 810. For example, Figure 14B and 14C , plate 806 is coupled only to the left side (eg, the front wall) of side wall 810 .

[0116] Figure 15 An example of an ABH assembly 800 is shown, wherein the body 802 includes two chambers 1500, 1502, which are separated from the end wall 808 ( Figure 8A ). In this example, chambers 1500, 1502 extend at an angle relative to axis 814. Each chamber 1500, 1502 has one or more plates 1504, 1506 (one of which is referenced in each chamber 1500, 1502). Any sound waves not attenuated in cavity 804 can enter the first chamber 1500 and the second chamber 1502, where the sound energy is absorbed by plates 1504, 1506. In the example shown, ABH assembly 800 includes damping material 818 between cavity 804 and chambers 1500, 1502.

[0117] Disclosed herein is an exemplary variable exhaust valve (VBV) assembly comprising a VBV port extending radially outward from the compressor section of a gas turbine engine and a door positioned at the outlet of the VBV port. Depending on the internal dimensions of the VBV port, flow conditions near the VBV port, and the closed position of the VBV door, the VBV port may generate significant noise at a resonant frequency. The resonant frequency may cause an increase in air pressure at the VBV assembly and propagate to surrounding hardware, such as low-pressure areas of the gas turbine engine (e.g., the supercharger section, the booster, or the core inlet section). Such oscillations may excite mechanical components of the engine, such as rotor blades, disks, and blisks, potentially degrading engine performance, damaging components, and increasing wear.

[0118] Some example VBV assemblies disclosed herein include an acoustic black hole (ABH) assembly coupled to a door. The ABH assembly includes a body and a plurality of plates (e.g., plates) coupled to an interior surface of the body. In some examples, the body of the ABH assembly extends circumferentially around the longitudinal axis of the gas turbine engine and defines a continuous ABH cavity. In some examples, the body of the ABH assembly corresponds to a first plug body included in a plurality of plug bodies. The first plug body is aligned with the transverse axis of the gas turbine engine and may have an open-top cylindrical shape. The dimensions of the plates of the ABH assembly vary radially outward along the depth of the body. The plates vibrate at a resonant frequency and convert acoustic energy from the VBV port into structural vibration energy and ultimately heat. The energy conversion and wave interaction provided by the ABH assembly attenuate noise associated with the resonant frequency of the VBV port. Thus, the ABH assembly can absorb noise and reduce and / or eliminate reflections of acoustic waves from the door of the VBV port.

[0119] The following items provide examples and example combinations disclosed herein:

[0120] A variable exhaust valve assembly for a gas turbine engine, the variable exhaust valve assembly comprising: a port extending outwardly from a main flow path of the gas turbine engine; a door positioned at an outlet of the port; and an acoustic black hole (ABH) assembly coupled to the door, the ABH assembly comprising a body and a plurality of plates coupled to an interior surface of the body, the body defining a cavity having a depth, each of the plurality of plates having a surface area, the plurality of plates being arranged such that the surface areas of the plurality of plates vary along the depth in a radially outward direction of the gas turbine engine.

[0121] A variable exhaust valve assembly according to any preceding clause, wherein the plurality of plates are arranged such that the surface area of ​​the plurality of plates increases in the radially outward direction along the depth.

[0122] A variable exhaust valve assembly according to any preceding clause, wherein the plurality of plates are disks having an aperture having an area, and wherein the plurality of plates are arranged such that the area of ​​the aperture decreases in a radially outward direction.

[0123] A variable exhaust valve assembly according to any preceding clause, wherein the plurality of plates are coupled to the interior surface of the body by posts.

[0124] A variable exhaust valve assembly according to any preceding clause, wherein the ABH assembly extends circumferentially about a longitudinal axis of the gas turbine engine.

[0125] A variable exhaust valve assembly according to any of the preceding clauses, wherein the inner surface of the body is a front inner surface, the body further comprising a rear inner surface and a radially outer surface, the rear inner surface being axially spaced apart from the front inner surface by a certain dimension.

[0126] A variable exhaust valve assembly according to any preceding clause, wherein said dimension is constant along said depth of said body.

[0127] A variable exhaust valve assembly according to any preceding clause, wherein said dimension varies along said depth of said body.

[0128] A variable exhaust valve assembly according to any preceding clause, wherein a first set of said plurality of plates extends axially outwardly from said front interior surface and a second set of said plurality of plates extends axially outwardly from said rear interior surface.

[0129] A variable exhaust valve assembly according to any preceding clause, wherein the front inner surface, the rear inner surface and the radially outer surface define a rectangular cross-section of the body.

[0130] A gas turbine engine comprises: a compressor section; and a variable exhaust valve (VBV) assembly, the variable exhaust valve (VBV) assembly comprising: a VBV door; a port extending radially outward between the compressor section and the VBV door, the port defining an exhaust flow path between the compressor section and the VBV door; and an acoustic black hole (ABH) assembly coupled to the VBV door, the ABH assembly comprising a body and a plurality of plates coupled to an interior surface of the body, the body defining a cavity having a depth, the plurality of plates having corresponding surface areas, the plurality of plates being arranged such that the surface areas vary along the depth in a radially outward direction of the gas turbine engine.

[0131] A gas turbine engine as claimed in any preceding clause, wherein the body extends circumferentially about a longitudinal axis of the gas turbine engine.

[0132] A gas turbine engine according to any preceding clause, wherein the interior surface of the body is a forward interior surface, the body further comprising an aft interior surface and a radially outer surface, the aft interior surface being axially spaced from the forward interior surface.

[0133] A gas turbine engine according to any preceding clause, wherein a first group of said plurality of plates is coupled to said forward interior surface and a second group of said plurality of plates is coupled to said aft interior surface, said plurality of plates corresponding to a ring surrounding said VBV door of said VBV assembly.

[0134] A gas turbine engine according to any of the preceding clauses, wherein the ABH assembly includes a plurality of baffles coupled to the VBV door, the front interior surface, the rear interior surface, and the radially outer surface, the plurality of baffles defining a plurality of ABH cavities, the plurality of baffles including a first baffle, a second baffle, and a third baffle, the first baffle and the second baffle being circumferentially spaced apart at a first angle, the second baffle and the third baffle being circumferentially spaced apart at a second angle, the first baffle and the second baffle defining a first ABH cavity, the second baffle and the third baffle defining a second ABH cavity, the first ABH cavity including a first interior volume, and the second ABH cavity including a second interior volume.

[0135] The gas turbine engine of any preceding clause, wherein the first angle is the same as the second angle, and the first internal volume is the same as the second internal volume.

[0136] A gas turbine engine as claimed in any preceding clause, wherein the first angle is different from the second angle, and the first internal volume is different from the second internal volume.

[0137] An acoustic black hole assembly for a variable exhaust valve assembly of a gas turbine engine, comprising: a body coupled to a door of the variable exhaust valve assembly, the body defining a cavity having a depth and an internal volume, the body including an opening positioned adjacent a hole in the door; and a plurality of plates coupled to an interior surface of the body, the plurality of plates extending outward from the interior surface, the plurality of plates being arranged such that respective surface areas of the plurality of plates vary in a radially outward direction of the gas turbine engine along the depth of the cavity.

[0138] An acoustic black hole assembly according to any of the preceding clauses, wherein the body is a first plug body included in a plurality of plug bodies, the first plug body corresponding to a cylinder with an open top aligned with a transverse axis of the gas turbine engine, the inner surface extending circumferentially around the transverse axis, the plurality of plates corresponding to disks having orifices aligned with the transverse axis, the plates being oriented substantially orthogonal to the transverse axis.

[0139] An acoustic black hole assembly according to any of the preceding clauses, wherein the plurality of plates are arranged such that the surface area of ​​the plurality of plates increases in the radially outward direction along the depth, and the aperture area of ​​the plurality of plates decreases in the radially outward direction along the depth.

[0140] Although certain example systems, apparatus, and articles of manufacture have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all systems, apparatus, and articles of manufacture that reasonably fall within the scope of the claims of this patent.

[0141] The following claims are hereby incorporated into this Detailed Description by reference, with each claim standing on its own as a separate embodiment of the disclosure.

Claims

1. A variable exhaust valve assembly for a gas turbine engine, characterized in that: The variable exhaust valve assembly comprises: a port extending groundwardly outwardly from a main flow path of the gas turbine engine; a door positioned at an exit of the port; and An acoustic black hole (ABH) assembly is coupled to the door, the ABH assembly comprising a body and a plurality of panels coupled to an interior surface of the body, the body defining a cavity having a depth, each of the plurality of panels having a surface area, the plurality of panels being arranged such that the surface areas of the plurality of panels vary along the depth in a radially outward direction of the gas turbine engine.

2. The variable exhaust valve assembly according to claim 1, characterized in that: wherein the plurality of plates are arranged such that the surface area of ​​the plurality of plates increases along the depth in the radially outward direction.

3. The variable exhaust valve assembly according to claim 1, characterized in that Wherein the plurality of plates are disks having an aperture having an area, and wherein the plurality of plates are arranged such that the area of ​​the aperture decreases in the radially outward direction.

4. The variable exhaust valve assembly according to claim 1, characterized in that wherein the plurality of plates are coupled to the interior surface of the body via posts.

5. The variable exhaust valve assembly according to claim 1, characterized in that Wherein the ABH assembly extends circumferentially about a longitudinal axis of the gas turbine engine.

6. The variable exhaust valve assembly according to claim 1, characterized in that Wherein the interior surface of the body is a front interior surface, the body further comprises a rear interior surface and a radially outer surface, the rear interior surface being axially spaced apart from the front interior surface by a certain dimension.

7. The variable exhaust valve assembly according to claim 6, characterized in that: wherein the dimension is constant along the depth of the body.

8. The variable exhaust valve assembly according to claim 6, characterized in that wherein the dimension varies along the depth of the body.

9. The variable exhaust valve assembly according to claim 6, characterized in that: Wherein a first set of the plurality of plates extends axially outward from the front interior surface and a second set of the plurality of plates extends axially outward from the rear interior surface.

10. The variable exhaust valve assembly according to claim 6, characterized in that wherein the front interior surface, the rear interior surface, and the radially outer surface define a rectangular cross-section of the body.

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