Variable exhaust valve assembly

Abstract

Disclosed herein is an example variable exhaust valve assembly for a gas turbine engine, including: a port extending radially outward from a compressor section of the gas turbine engine, the port defining a variable exhaust valve cavity, the port resonating at a resonant frequency based on operating conditions of the gas turbine engine; and an acoustic suppressor positioned on a wall of the port, the acoustic suppressor extending circumferentially along the wall by a length greater than a cross-sectional width of the acoustic suppressor, the acoustic suppressor defining a resonant cavity based on the length and the cross-sectional width, the acoustic suppressor including a perforated portion, the acoustic suppressor being tuned to resonate at a resonant frequency based on the length and the perforated portion.

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 some of the most widely used power generation technologies, and are commonly used in aircraft and power generation applications. Turbine engines generally include a fan and a core arranged in flow communication with each other. The core of a turbine engine generally includes a compressor section, a combustion section, a turbine section located on the same axis as the compressor section, and an exhaust section in serial flow order. Generally speaking, a casing or housing surrounds the core of the turbine engine. 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 an example gas turbine engine including a variable exhaust valve assembly.

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

[0006] Figure 3B Yes Figure 2 A cross-sectional front view of a compressor with a variable exhaust valve assembly.

[0007] Figure 4 is used for Figure 2 A perspective view of a known acoustic liner for a variable exhaust valve assembly.

[0008] Figure 5 yes Figure 1 A partial cross-sectional side view of a compressor of an example gas turbine engine including a variable exhaust valve assembly having an acoustic resonator according to the teachings disclosed herein.

[0009] Fig. 6A yes Figure 5 A perspective view of a portion of an acoustic resonator.

[0010] Figure 6B yes Figure 5 A perspective view of another portion of the acoustic resonator.

[0011] Figure 6C yes Figure 6B Front view of a portion of .

[0012] Fig.6D yes Figure 5 A front view of another part of the acoustic resonator.

[0013] Figure 7 yes Figure 5 and Figures 6A-6D A partial front view of the various perforation shapes and patterns that can be achieved with an acoustic resonator.

[0014] The drawings are not drawn to scale. On the contrary, the thickness of the layer or region may be magnified in the drawings. Although the drawings show layers and regions with clear lines and boundaries, some or all of these lines and / or boundaries may be idealized. In fact, the boundaries and / or lines may be unobservable, mixed and / or irregular. In general, the same reference number will be used to refer to the same or similar parts throughout the drawings and the accompanying written description. As used in this patent, it is stated that any part (e.g., layer, film, zone, region or plate) is located on another part in any way (e.g., positioned, located, arranged or formed on another part, etc.), indicating that the referenced part is in contact with another part, or the referenced part is located above another part, and there are one or more intermediate parts in between. As used herein, unless otherwise specified, connection references (e.g., attachment, connection, connection and engagement) may include intermediate members between the elements referenced by the connection reference and / or relative movement 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, a definition stating that any part is "in contact with" another part means that there is no intermediate part between the two parts.

[0015] Unless otherwise expressly stated, 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 in the claims by a different descriptor, such as "second" or "third." In this case, it should be understood that these descriptors are only used to explicitly identify those elements that may share the same name.

[0016] Throughout the specification and claims, approximate 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. Therefore, a value modified by one or more terms (such as "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.).

[0017] 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 to 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.

[0018] Various terms are used herein to describe the orientation of features. Generally, the drawings are labeled with reference to the axial direction, radial direction, and circumferential direction of the vehicle with which features, forces, and moments are associated. Generally, the drawings are labeled with a set of axes, including an axial axis A, a radial axis R, and a circumferential axis C.

[0019] In the following detailed description, reference is made to the accompanying drawings forming a part of this document, in which specific examples that can be practiced are shown by way of example. The description of these examples is detailed enough to enable those skilled in the art to practice this subject matter, 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 subject matter described in this disclosure. Certain features of the different aspects described below can be combined to form yet other new aspects of the subject matter discussed below. DETAILED DESCRIPTION

[0020] A turbine engine, also referred to herein as a gas turbine engine, is an internal combustion engine that uses the atmosphere as a flowing fluid. In operation, the atmosphere 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, before entering the turbine section, the pressurized air is combined with fuel and ignited to produce a high-temperature, high-pressure gas flow (e.g., hot combustion gases). 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 produce a spool work output that powers the corresponding compressor. The 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, the turbine engine may include one spool or more than two spools.

[0021] 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., a certain amount of time is required for the speed to adjust to the new balance). However, the compressor cannot stop producing pressurized air for fuel combustion during operation. Such a result may cause the turbine to stop producing power to drive the compressor, thereby causing the compressor itself to stop compressing air. Therefore, throttling changes may cause compressor instability, 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 airflow 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 airflow through the compressor (e.g., complete interruption, most interruption, other partial interruption, etc.).

[0022] Variable exhaust valves (VBVs) are typically integrated into the compressor (e.g., at the downstream end of the LP compressor) to improve efficiency and limit possible stalls. The VBV enables the turbine engine to exhaust air from the compressor section of the turbine engine during operation. An example VBV assembly includes a VBV port (e.g., an opening, an air exhaust slot, etc.), including a VBV cavity extending from the compressor housing and a VBV door opened via actuation. In other words, the VBV is configured as a cavity with a door that opens to provide an exhaust flow path to exhaust compressed air between the supercharger (e.g., a low-pressure compressor) of the gas turbine and the core engine compressor. For example, the VBV door can be actuated during a speed mismatch between the LP spool and the HP spool. For example, during a deceleration transient, the HP spool may rotate at a speed lower than the LP spool. Opening the VBV port allows the LP spool to maintain a specific stall margin while reducing the amount of air flowing through the HP compressor by directing some airflow to the fan exhaust area. Therefore, the VBV door enables the LP spool (e.g., supercharger) to operate at a lower operating line and away from potential unstable or stalling conditions.

[0023] In some VBV ports, the VBV door is not flush with the compressor housing, resulting in the exhaust cavity being open to the main flow path within the compressor. When the VBV door is closed, the air of the main flow path flows through the opening of the VBV cavity. This causes the VBV port to acoustically resonate at a fixed frequency or a set of frequencies, similar to blowing into an empty bottle. These frequencies are generally referred to as Rossiter tones. More specifically, a shear layer of the main flow path forms across the opening of the VBV cavity. The shear layer has oscillations that couple with the non-flowing air within the VBV cavity. These oscillations can be amplified and / or acoustically excite the air in the engine core based on the geometry of the VBV cavity. At certain resonant frequencies, the acoustic excitation causes mechanical vibrations of the rotor system (e.g., rotor blades, rotor disks, rotor blisks (integrated rotor disks and blades), etc.) in the LP compressor. In some cases, the mechanical vibrations propagate and / or intensify along the rotor system upstream toward the initial rotor disk. This mechanical excitation of the LP compressor may damage the rotor system and / or reduce supercharger performance. For example, one or more rotor blades of the initial rotor stage may break due to excessive mechanical vibrations generated by the acoustic resonance of the closed VBV port (e.g., VBV cavity). Therefore, a new VBV assembly is needed to reduce the resonant frequency of the VBV cavity when the VBV door is closed.

[0024] The example VBV assembly disclosed herein can dampen the acoustic response of the air within the VBV cavity, thereby reducing the oscillation of the air within the supercharger. Thus, the disclosed examples enable the manufacture of a VBV assembly that reduces the vibration of the LP compressor or supercharger at various resonant frequencies of the VBV cavity. In other words, the example VBV assembly disclosed herein reduces vibration damage to the rotor system of the supercharger while improving the aerodynamic performance and / or efficiency of the turbine engine.

[0025] Certain examples disclosed herein enable VBV assemblies in which a contoured (e.g., wavy, corrugated, etc.) surface having perforations (e.g., holes, pores, etc.) is attached to the wall of a VBV port to reduce the VBV cavity acoustic resonant response. Example contoured surfaces, acoustic liners, or mufflers include perforations or holes to reduce the resonant response of the enclosed VBV cavity. In some examples, the muffler is incorporated into the casting process of the VBV assembly to be integrated with the VBV port as a single unified component. Additionally or alternatively, the muffler is a separate component that is coupled to the wall of the VBV port. Thus, the acoustic liner or resonator can be retrofitted into the wall of an existing VBV assembly.

[0026] Certain examples disclosed herein enable VBV assemblies in which contoured acoustic liners can be specifically tuned based on the frequency of the VBV cavity. For example, the dimensions (e.g., internal volume) of different mufflers of the wall liner can be changed and adjusted based on the resonant frequency that the VBV cavity is most likely to produce. Thus, certain examples attenuate aeroacoustic excitations in the VBV assembly and supercharger flow path, improve aerodynamic efficiency, and minimize or otherwise reduce aeroacoustic-mechanical vibrations of the rotor system of the LP compressor.

[0027] Referring now to the drawings, wherein like numerals refer to like elements throughout, Figure 1 1 is a schematic cross-sectional view of an example high bypass turbofan type gas turbine engine ("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. In general, 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.

[0028] Generally speaking, the turbofan engine 110 includes a core turbine 114 (e.g., a gas turbine engine) located downstream of a fan section 116. The core turbine 114 includes a substantially tubular outer casing 118 that defines an annular inlet 120. The outer casing 118 may be formed of a single casing or multiple casings. The outer casing 118 encloses, in serial flow relationship: a compressor section having a supercharger 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 spool 134") drivingly couples the HP turbine 128 and the HP compressor 124. A low pressure shaft or spool 136 ("LP shaft 136") drivingly couples the LP turbine 130 and the LP compressor 122. The LP shaft 136 may also be coupled to a fan spool or 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 may be coupled to the fan shaft 138 via a reduction gear 139 (e.g., an indirect drive or gear drive configuration).

[0029] like Figure 1 As shown, fan section 116 includes a plurality of fan blades 140 that are coupled to and extend 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. In addition, a downstream section 146 of nacelle 142 may surround an outer portion of core turbine 114 to define a bypass airflow passage 148 therebetween.

[0030] like Figure 1As shown, air 150 enters an inlet portion 152 of the turbofan engine 110 during operation of the turbofan engine 110. 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 vanes 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 vanes 174 and HP compressor rotor blades 176 coupled to the HP spool 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.

[0031] The combustion gases 160 flow through the HP turbine 128, wherein 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 therefrom. This energy extraction supports the operation of the HP compressor 124. The combustion gases 160 then flow through the LP turbine 130, wherein one or more successive stages of LP turbine stator blades 162 and LP turbine rotor blades 164 coupled to the LP shaft 136 extract a second portion of thermal and / or kinetic energy therefrom. 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. The combustion gases 160 then exit the core turbine 114 through the exhaust section 132 of the core turbine 114. A turbine frame 161 having a fairing assembly is located between the HP turbine 128 and the LP turbine 130. The turbine frame 161 serves as a support structure, connects the rear bearing of the high pressure shaft to the turbine housing, and forms an aerodynamic transition duct between the HP turbine 128 and the LP turbine 130. The fairing forms a flow path between the high and low pressure turbines and may be formed using a metal casting (e.g., a nickel-based cast metal alloy, etc.).

[0032] The core turbine 114 is used for similar purposes with the turbofan engine 110 and is exposed to similar environments in land-based gas turbines, turbojet engines (where the ratio of the first portion 154 of air 150 to the second portion 156 of air 150 is less than that in a turbofan engine), and unducted fan engines (where the fan section 116 does not have a nacelle 142). In turbofan engines, turbojet engines, and unducted fan engines, a speed reduction device (e.g., a speed reduction gear 139) may be included between any shaft and spool. For example, the speed reduction gear 139 is provided between the LP shaft 136 and the fan shaft 138 of the fan section 116.

[0033] 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 with the turbine housing and 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.

[0034] Figure 2 is a turbine engine (e.g. Figure 1 1 is an illustration of a partial cross-sectional view of an example compressor 200 of a turbofan engine 110 in FIG. 1 , including an example LP compressor or supercharger section 202 and an example HP compressor section 204 . 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 , a housing 208 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 connection mechanism. The housing 208 surrounds the rotor blades 210a and stator vanes 210b of the compressor 200. In operation, the rotor blades 210a rotate, thereby pushing air downstream. The stator vanes 210b redirect and reduce the airflow velocity, thereby increasing the downstream pressure. The housing 208 defines an example main flow path 212 (e.g., a first flow path) of airflow through the compressor 200 (e.g., the turbofan engine 110).

[0035] like Figure 2 As shown in the example, the VBV assembly 213 of the turbine engine includes a VBV port 214 (e.g., a passage, opening, duct, etc.) for diverting air from the primary flow path 212 and bypassing 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 front VBV wall 220a and a rear VBV wall 220b extending radially outward between the supercharger section 202 and the VBV port outlet 218. In some examples, the front VBV wall 220a and the rear VBV wall 220b define an annular geometry of the VBV port 214.

[0036] exist Figure 2In the example shown, the VBV port 214 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 rods (e.g., a bell crank, etc.), connecting rods, 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 may be actuated (e.g., moved, translated, rotated, etc.) between the open position 226 and the closed position.

[0037] exist Figure 2 In the example shown, the VBV door 222 and the VBV actuation system 224 are located adjacent to the VBV port outlet 218. The VBV actuation system 224 moves the VBV door 222 (e.g., a blocking door, etc.) to 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 the air is relatively stagnant on average in the VBV port 214 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. Thus, a shear layer of airflow extending across the opening 230 of the VBV port 214 substantially confines air pockets within the VBV cavity 228. The airflow 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. Such acoustic resonance of the VBV cavity 228 may lead to acoustic excitation and compressor instability in the supercharger section 202 . Beneficially, the example VBV assemblies disclosed herein include an acoustic liner to dampen the acoustic resonance of the VBV cavity 228 .

[0038] Figure 3A yes Figure 2 A side view of an example compressor 200 including a compressor that may be used in a turbine engine (e.g., Figure 1 and / or a first variable exhaust valve assembly 213 implemented in the turbofan engine 110 in 2. Figure 3B It is taken along line AA Figure 3A A cross-sectional front view of an example compressor 200 is shown. Figure 3A and 3B In the example shown, the VBV door 222 is in the open position 226. Figure 3B Not visible in.

[0039] 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 first VBV assembly 213a 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 port 214 is formed at the transition point 206 between the supercharger housing 208a and the compressor housing 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., brazed, welded, bolted, etc.) to the housing 208.

[0040] 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. In some examples, each VBV port 214 includes a door that can be actuated between an open and closed position to adjust the discharge flow of the VBV assembly 213 based on the target discharge flow 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 to define the VBV ports 214. That is, the baffles 300 circumferentially separate adjacent VBV ports 214. The plurality of baffles 300 are circumferentially spaced about the compressor 200 at substantially similar axial and radial positions.

[0041] exist Figure 3B In the example shown, the supercharger housing 208a and the compressor housing 208b include an example outer surface 302 and an example inner surface 304. Figure 3B In the example, Figure 3BDimension 306 corresponds to the thickness of the housing 208a, 208b and / or the radial length of the VBV port 214. For example, the compressor housing 208b expands radially outward by dimension 306 from the inner surface 304 to the outer surface 302. In some examples, the VBV port 214 extends radially beyond the outer surface 302 and has a radial length greater than dimension 306.

[0042] exist Figure 3B In the example shown, the VBV ports in the VBV ports 214 include Figure 2 In some examples, the VBV ports 214 have similar sizes and the VBV cavities 228 have similar volumes. Alternatively, the VBV ports in the VBV ports 214 may have variable sizes and the VBV cavities in the VBV cavities 228 may have different 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.

[0043] Various example VBV components according to the teachings of the present disclosure are described in more detail below. The examples disclosed below apply to Figure 2 , 3A and 3B . Thus, the examples disclosed below include an example housing 208 (e.g., a supercharger housing 208a and a compressor housing 208b) defining a main 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. In addition, the examples disclosed herein may be implemented on compressors having a variety of configurations, such as including one or more VBV ports, compressor stages, etc. In addition, the examples disclosed herein may be applied to a variety of turbine engines, such as a multi-spool turbine engine, a turboshaft engine, a turbine engine with one compressor section, etc. The examples disclosed below may include a controller to determine to actuate the VBV assembly disclosed herein.

[0044] Figure 2 , 3A The VBV port 214 of the VBV assembly 213 of FIG. 3B can resonate at an acoustic frequency based on the shape of the closed VBV cavity 228 (including the flow width length 232 of the opening 230 and the flow velocity adjacent to the main flow path of the cavity). That is, when the VBV door 222 is in the closed position and air flows through the opening 230 ( Figure 2 )hour, Figure 2The VBV port 214 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.).

[0045] FIG. 4 is a partial perspective view of a known acoustic liner 400 that may be used in certain engine assemblies (eg, Figure 1 The acoustic liner 400 includes a first plate 402 (e.g., a top plate) and a second plate 404 (e.g., a bottom plate). The first plate 402 includes a plurality of perforations 406 to allow air and sound waves to enter the acoustic liner 400. In addition, the acoustic liner 400 includes a core layer 408 positioned between the first plate 402 and the second plate 404. The core layer 408 of FIG. 4 is a honeycomb core layer made of one or more materials, such as a composite material, aluminum, fiberglass, etc. The core layer 408 includes a plurality of chambers 410 (e.g., honeycomb chambers) extending a dimension 412 between the first plate 402 and the second plate 404. In some examples, the dimension 412 corresponds to the depth of the chamber 410 and / or the thickness of the core layer 408, such as 1 inch, 3 inches, etc.

[0046] The acoustic liner 400 may be referred to as a quarter wave plate because the dimension 412 is one quarter of the wavelength distance associated with the frequency to be attenuated. For example, when the acoustic liner 400 is to eliminate noise having a frequency of 1000 Hertz (Hz) and a wavelength distance of 34 centimeters (cm), the dimension 412 of the acoustic liner 400 is approximately 8.5 cm (e.g., + / - 0.1 cm, etc.). The acoustic liner 400 includes perforations 406 to allow sound waves (e.g., air pressure fluctuations) to enter the chamber 410. The sound waves are then suppressed based on the dimension 412 (e.g., depth) of the chamber 410. More specifically, the sound waves may be reflected from the walls of the chamber 410 to produce a resonant frequency that cancels out the frequency of the sound waves entering the perforations 406. The acoustic liner 400 includes a pattern 414 of perforations 406 that corresponds to an array of circular holes, elliptical holes, or other shaped holes (e.g., a plurality of holes positioned in an array pattern). The shape of the perforations 406 and / or the layout of the pattern 414 define the open area of ​​the first plate 402. In some examples, the open area can be a major contributing factor to the suppression characteristics of the acoustic liner 400. In the illustration of FIG.

[0047] However, a quarter-wavelength resonant liner (such as acoustic liner 400) cannot effectively reduce or eliminate the VBV port 214 ( Figure 2) acoustic resonance. For example, the resonant frequency of a VBV port (e.g., VBV port 214) may be associated with a wavelength distance in the range of 1 to 5 feet. Thus, the dimension 412 of the acoustic liner 400 may be in the range of 3 to 15 inches. Thus, an acoustic liner 400 having such a thickness is too thick to be integrated with the front wall 220a, rear VBV wall 220b of the VBV port without restricting exhaust airflow and degrading the performance of the VBV assembly 213. Therefore, retrofitting the acoustic liner 400 to an existing VBV port (e.g., Figure 2 VBV port 214) may be Figure 1 The performance of the compressor 200 and the turbofan engine 110 is negatively affected.

[0048] Figure 5 is a cross-sectional view of an example VBV assembly 500 including a plurality of example resonators 502 (eg, acoustic resonators and / or acoustic suppressors) according to the teachings disclosed herein. Figure 5 Many components of the example VBV assembly 500 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 below. 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 5 A similar structure in would use Figure 2 , 3A Same reference numbers as in 3B. For the figures disclosed herein, like numbers refer to like components throughout the figures.

[0049] The plurality of resonators 502 includes a plurality of first resonators 502a (e.g., a first plurality of acoustic suppressors and / or acoustic resonators) and a plurality of second resonators 502b (e.g., a second plurality of acoustic suppressors and / or acoustic resonators). The plurality of first resonators 502a are coupled to a front VBV wall 503a of the VBV port 503. In addition, the plurality of second resonators 502b are coupled to a rear VBV wall 503b of the VBV port 503. In some examples, the VBV port 503 implements Figure 2 , 3A , 3B VBV port 214. In addition, Figure 5 The front VBV wall 503a and the rear VBV wall 503b can be realized Figure 2 , 3A , the front VBV wall 220a and the rear VBV wall 220b of 3B.

[0050] exist Figure 5In the example shown, three first resonators 502a and four second resonators 502b are included in the VBV port 503. For example, the plurality of first resonators 502a include a first resonator 504 (e.g., a first acoustic resonator), a second resonator 506 (e.g., a second acoustic resonator), and a third resonator 508. Alternatively, more or fewer first resonators 502a and second resonators 502b (e.g., one, four, six, etc.) may be included in the VBV assembly 500. The plurality of first resonators 502a are coupled to a front VBV wall 503a of the VBV port 503. In addition, the plurality of second resonators 502b are coupled to a rear VBV wall 503b of the VBV port 503. The description of the plurality of first resonators 502a also applies to the plurality of second resonators 502b. In addition, unless otherwise stated, the description of the first resonator 504 also applies to Figure 5 Other resonators (eg, the second resonator 506, the third resonator 508, etc.).

[0051] exist Figure 5 In the example shown, the VBV assembly 500 includes a contoured surface 510 coupled to the front VBV wall 220a. The contoured surface 510 forms a resonant cavity 512 of the first resonator 504 (e.g., an acoustic suppressor). The resonant cavity 512 includes a volume of air and / or damping material (e.g., a bulk absorber, steel wool, etc.) between the contoured surface 510 and the front VBV wall 220a. More specifically, the contoured surface 510 includes a first valley 514a, a second valley 514b, and a ridge 516 that defines the resonant cavity 512. In some examples, the contoured surface 510 and the front VBV wall 220a are a single, unified component formed in the same manufacturing process. For example, the contoured surface 510, the front VBV wall 220a, and / or a portion of the supercharger housing 208a are made by a die casting process and / or an additive manufacturing process. In some examples, the contoured surface 510 is a corrugated, ridged, or grooved metal plate coupled to the front VBV wall 220a via a fastening method such as welding, brazing, bonding, etc. Thus, the contoured surface 510 may be connected to the front VBV wall 220a at the first valley 514a, the second valley 514b, and / or other valleys of the contoured surface 510.

[0052] exist Figure 5 In the example shown, the contoured surface 510 is wavy or corrugated to form a resonant cavity 512. In addition, when the VBV gate 222 is in Figure 2When the first resonator 504 and the second resonator 502a and the second resonator 502b are in the open position 226, the curvature of the contoured surface 510 can reduce the airflow resistance along the exhaust flow path 216. In some examples, the cross-sectional area of ​​the VBV port 503 is consistent in the radial direction based on the curvature of the first resonator 502a and the second resonator 502b. In some examples, the contoured surface 510 is relatively flat and / or aligned with the front VBV wall 220a. Therefore, the first resonator 504 and the resonance cavity 512 can be defined based on a baffle coupled to the contoured surface 510 and the front VBV wall 220a (e.g., at a position similar to the first valley 514a, the second valley 514b, etc.). As described below in conjunction with Fig. 6A As further described, the contour surface 510 is Figure 3B The first resonator 504 extends circumferentially between adjacent baffles 300. Thus, the first resonator 504 extends along the front VBV wall 220a and around Figure 1 A centerline axis 112 of turbofan engine 110 extends circumferentially.

[0053] Figure 5 The first resonator 504 of the illustrated example includes one or more holes or perforations 518 in the contoured surface 510. In some examples, the perforations 518 are positioned between the ridge 516 and the second valley 514b (e.g., downstream side) of the first resonator 504. The perforations 518 are positioned downstream of the ridge 516 relative to the exhaust flow path 216 to reduce the amount of air flowing when the VBV gate 222 is in the Figure 2 In some examples, the additional perforations 518 are positioned between the ridge 516 and the first valley 514a (e.g., the upstream side) of the first resonator 504. In some examples, the perforations 518 positioned upstream of the ridge 516 are less than the perforations 518 positioned downstream of the ridge 516. Figure 5 The perforations 518 of the illustrated example may have similar or different shapes and / or patterns. Figure 7 Different shapes and / or patterns of perforations 518 are further described.

[0054] The perforations 518 cause the first resonator 504 to suppress the VBV cavity 520 at a pitch or resonant frequency corresponding to the first resonator 504 (eg, Figure 2 , 3A-3B VBV cavity 228, etc.). When the VBV door 222 is in the closed position 522, air can circulate within the VBV cavity 520 and / or remain relatively stagnant (e.g., zero meters per second (m / s), 0.1 m / s, etc.) compared to the main flow path 212. As the VBV port 503 resonates, the acoustic pressure fluctuations drive the oscillating flow into and out of the resonant cavity 512 via the perforations 518. The resonant frequency of the first resonator 504 can be tuned based on the volume of the resonant cavity 512, the number of perforations 518, the shape of the perforations 518, etc. For example, increasing the volume of the resonant cavity 512 will reduce the resonant frequency. Therefore, the first resonator 504 can be tuned to the same frequency as the resonant frequency of the VBV port 503. When the first resonator 504 resonates at a frequency that matches the frequency of the VBV port 503, the flow oscillates bidirectionally through the perforations 518 and encounters resistance that dampens the sound pressure level associated with the resonance of the VBV cavity 520. This further reduces the sound pressure level that exits the VBV port 503 and excites Figure 2 Acoustic vibrations of the supercharger section 202.

[0055] In some examples, each resonator 502 (e.g., the first resonator 504, the second resonator 506, the third resonator 508, etc.) is tuned to the same frequency corresponding to the resonant frequency of the VBV port 503. In some examples, a bulk acoustic absorber (e.g., metal foam, etc.) is positioned within the resonant cavity 512 near the perforation 518 to further suppress the acoustic energy of the VBV port 503. In some examples, adjacent first resonators 502a can be connected. For example, an opening can be included between the first resonator 504 and the second resonator 506 to form a combined resonator. Thus, the resonant cavity 512 can extend between the first resonator 504 and the second resonator 506. In addition, the combined resonator can produce a resonant frequency that is lower than the resonant frequency of the individual first resonators 504.

[0056] Fig. 6A yes Figure 5 A perspective view of a first portion 600a of a plurality of second resonators 502b. Fig. 6A In the example shown, the first portion 600a includes three second resonators 502b. For example, the plurality of second resonators 502b include a first resonator 602a (e.g., a first acoustic resonator), a second resonator 604a (e.g., a second acoustic resonator), and a third resonator 606 (e.g., a third acoustic resonator). Unless otherwise specified, the description of the first resonator 602a also applies to Fig. 6A Other resonators (eg, the second resonator 604a, the third resonator 606, etc.).

[0057] The plurality of second resonators 502b extend circumferentially along a dimension 607 (e.g., length) between a first end 608 and a second end 610. The first end 608 is positioned adjacent to the first baffle 612, while the second end 610 is positioned adjacent to the second baffle 614. In some examples, the second resonators 502b are coupled to the first baffle 612 and the second baffle 614 by fasteners such as welding, brazing, etc. The first baffle 612 and the second baffle 614 may correspond to Figure 3B Thus, the volume between the first separator 612 and the second separator 614 may correspond to Figure 2 and 3B The VBV cavity 228 and / or Figure 5 VBV cavity 520.

[0058] exist Fig. 6A In the example shown, the second resonator 502b of the first portion 600a is shown extending along an approximately straight and / or orthogonal path between the first baffle 612 and the second baffle 614. However, in some examples, the second resonator 502b is located along the VBV port (e.g., Figure 3B The curved shape of the VBV port 503) extends circumferentially. In other words, Fig. 6A The dimension 607 corresponds to the linear length of the second resonator 502b. However, in some examples, the dimension 607 corresponds to the arcuate length of the second resonator 502b.

[0059] exist Fig. 6A In the example shown, the first resonator 602 a includes a first pattern 616 of perforations 518 . Fig. 6A The first pattern 616 of the first resonator 604a is a row of perforations 518 positioned at a first perforated portion 618a of the first resonator 602a. In contrast, the first resonator 602a includes a first non-perforated portion 620a that is solid or uniform over a surface area. The first perforated portion 618a extends circumferentially along a first dimension 607a, and the first non-perforated portion 620a extends circumferentially along a second dimension 607b. In some examples, the first dimension 607a and the second dimension 607b correspond to the net length of the second resonator 502b (e.g., dimension 607). In addition, the second resonator 604a includes a second perforated portion 618b and a second non-perforated portion 620b. In the example shown, the second perforated portion 618b extends circumferentially along a third dimension 607c, and the second non-perforated portion 620b extends circumferentially along a fourth dimension 607d. In some examples, the first perforated portion 618a of the first resonator 602a is located along the first dimension 607a and the second perforated portion 618b of the second resonator 604a is located along the third dimension 607c. In some examples, the third dimension 607c is different (eg, shorter or longer) than the first dimension 607a.

[0060] Fig. 6A The first resonator 602a in the embodiment includes a first non-perforated portion 620a for reflecting acoustic oscillations within the first resonant cavity 622a. The reflection of the acoustic waves within the first resonant cavity 622a causes the first resonator 602a to produce an acoustic tone at a specific resonant frequency. The number of perforations 518 in the first pattern 616 tunes the resonant frequency of the first resonator 602a. Therefore, the first dimension 607a and the second dimension 607b can be adjusted to tune the resonant frequency of the first resonator 602a. For example, when the first dimension 607a is increased and the first pattern 616 includes a plurality of perforations 518 positioned at Fig. 6A With additional perforations to the circumferential right of the perforations 518 shown in FIG, the resonant frequency of the first resonator 602a increases.

[0061] In addition, the cross-sectional area of ​​the first resonant cavity 622a can define the resonant frequency of the first resonator 602a. For example, the cross-sectional area of ​​the first resonant cavity 622a can be increased to reduce the resonant response of the first resonator 602a. Therefore, the dimension 607 (e.g., the second dimension 607b) and / or the cross-sectional area of ​​the first resonator 602a (e.g., the first resonant cavity 622a) can be adjusted to tune the resonant frequency of the first resonator 602a. In some examples, the cross-sectional area of ​​the first resonator 602a and / or the first resonant cavity 622a is defined by the cross-sectional width 623a and the cross-sectional height 623b. In addition, the dimension 607 (e.g., the length) of the first resonator 602a is greater than the cross-sectional width 623a and / or the cross-sectional height 623b of the first resonator 602a and / or the first resonant cavity 622a.

[0062] exist Fig. 6A In the example shown, the first resonator 602a includes a first resonant cavity 622a, the second resonator 604a includes a second resonant cavity 624a, and the third resonator 606 includes a third resonant cavity 626. In addition, the second resonator 604a includes a second pattern 628 of the perforations 518, and the third resonator 606 includes a third pattern 630 of the perforations 518. In some examples, the first resonator 602a, the second resonator 604a, and the third resonator 606 have the same resonant frequency. For example, the first dimension 607a and the second dimension 607b of each of the first resonator 602a, the second resonator 604a, and the third resonator 606 can be the same, and the volumes of the first resonant cavity 622a, the second resonant cavity 624a, and the third resonant cavity 626 can be the same. Alternatively, the first dimension 607a of the first resonator 602a and the volume of the first resonant cavity 622a can be reduced to achieve similar resonant frequencies. For example, the first resonator 602a may include partitions or dividing walls within the first resonant cavity 622a to reduce the size 607 of the first resonator 602a.

[0063] exist Fig. 6A In the example shown, the first pattern 616 of the first resonator 602a is similar to the third pattern 630 of the third resonator 606. The second pattern 628 of the second resonator 604a is different from the first pattern 616 and / or the third pattern 630. For example, the second pattern 628 corresponds to an array of perforations 518, wherein the number of perforations 518 is greater than the first pattern 616. The pattern and / or number of perforations corresponds to the open area of ​​the resonator (e.g., a quarter-wave resonator), and the acoustic response (e.g., acoustic impedance, acoustic resistance, acoustic reactance, etc.) of the resonator is based on the open area. Therefore, Fig. 6A The first resonator 602a and the second resonator 604a in the embodiment of the present invention emit similar resonant frequencies due to the second dimension 607b (e.g., the length of the first non-perforated portion 620a), but respond differently to acoustic energy. For example, based on the second pattern 628, the second resonator 604a can provide a greater acoustic impedance than the first resonator 602a. As used herein, acoustic impedance refers to a measure of the resistance presented by a system or damper (e.g., a resonator) to an acoustic flow (e.g., a resonant pressure oscillation) applied to the damper.

[0064] Figure 6B yes Figure 5 6 is a perspective view of a second portion 600b of the plurality of second resonators 502b. Figure 6C yes Figure 6B A front view of the second portion 600b. Fig.6D yes Figure 5 A front view of a third portion 600d of the plurality of second resonators 502b. Figure 6B-6D In the example shown, the second 600b and third sections 600d include three second resonators 502b. Figure 6B and 6C The plurality of second resonators 502b include a fourth resonator 602b, a fifth resonator 604b, and a third resonator 606b. Fig. 6A ). Fig.6D The plurality of second resonators 502b include a fourth resonator 602b, a sixth resonator 604d, and a third resonator 606( Fig. 6A ).

[0065] exist Figure 6B-6D In the example shown, adjacent second resonators 502b are connected together to reduce the resonant frequency. For example, the second end 610 of the fifth resonator 604b can be bent and connected to the second end 610 of the fourth resonator 602b. Therefore, the fourth resonant cavity 622b of the fourth resonator 602b and the fifth resonant cavity 624b of the fifth resonator 604b can be connected together to define a continuous space or volume in which acoustic oscillations can be freely transmitted. Alternatively, as Fig.6DAs shown, the second end 610 of the sixth resonator 604d may have an approximately 90 degree turn to couple to the second end 610 of the fourth resonator 602b.

[0066] exist Figure 6B and 6C In the example shown, a partition or dividing wall 632 is positioned at the second end 610 of the first resonator 602a and the second end 610 of the second resonator 604a to separate the fourth resonant cavity 622b and the fifth resonant cavity 624b. The dividing wall 632 is positioned at a distance 634 from the second partition 614 to provide a bending length 636 of the third non-perforated portion 620c of the fifth resonator 604b. The bending length 636 is longer than the second dimension 607b of the third resonator 606, thereby enabling absorption at lower frequencies (e.g., relative to the third resonator 606).

[0067] exist Fig.6D In the example shown, the sixth resonator 604d is angled approximately 90 degrees adjacent to the second partition wall 614. Thus, the sixth resonator 604d is rectangular. In addition, the fourth non-perforated portion 620d of the sixth resonator 604d extends and curves along a length 638 (e.g., a rectangular length, an orthogonal length, etc.) between the second perforated portion 618b and the partition wall 632. The length 638 is greater than Figure 6B and 6C The bending length of the fifth resonator 604b is long. Therefore, the sixth resonator 604d can suppress a lower frequency than the fifth resonator 604b.

[0068] exist Figure 6B-6D In the example shown, the dividing wall 632 defines a length 640 of the third non-perforated portion 620c of the fourth resonator 602b, which tunes the fourth resonator 602b to a higher frequency (e.g., relative to the fifth resonator 604b and the third resonator 606). Thus, the length 640 enables the fourth resonator 602b to absorb higher modes (e.g., eigenmodes) corresponding to higher resonant frequencies. In addition, consecutive pairs of resonators can be coupled together to allow the second resonator 502b to suppress multiple potential resonant frequencies of interest for a particular application (e.g., multiple VBV resonant modes under a given operating engine condition, and / or multiple operating conditions, such as takeoff, climb, landing, cruise, etc.).

[0069] In some examples, the first end 608 of the fifth resonator 604b and the first end 608 of the third resonator 606 are also coupled together. In addition, the second pattern 628 of the fifth resonator 604b is removed, and the third pattern 630 of the third resonator 606 is relocated to the second end 610. In addition, the partition wall 632 is removed or relocated to the third resonator 606. Therefore, the fourth resonant cavity 622b, the fifth resonant cavity, and the third resonant cavity 626 can form a pair of resonators, one of which has a continuous "S"-shaped volume, which achieves a lower frequency than the above. In such an example, since the volume of the resonant length of the resonant cavity can be doubled or tripled, the resonant frequency achieved can be at, respectively, Fig. 6A The resonance frequency of the first resonator 602a, the second resonator 604a or the third resonator 606 is between one third and one half.

[0070] Figure 7 It is possible Figure 5 , 6A -6D is a partial front view of other example shapes and / or patterns of perforations 518 of the plurality of resonators 502. Figure 7 The examples shown include circular perforations 702, rectangular perforations 704, square perforations 706, straight slot perforations 708, diamond perforations 710, hexagonal perforations 712, cross perforations 714, triangular perforations 716, elliptical perforations 718, and skew slot perforations 720. In some examples, the implementation of different perforations in perforations 702-720 can provide different acoustic impedance characteristics of resonator 502. As used herein, acoustic impedance refers to the resistance of sound waves between VBV cavity 520 and Figure 5 Energy transfer between the resonant cavities 512. Figure 5 The acoustic impedance of the first resonator 504 affects the amount of acoustic energy that the liner is able to absorb. Therefore, increasing the acoustic impedance of the first resonator 504 can reduce the sound pressure level associated with acoustic oscillations from the VBV port 503, which is based on the resonant frequency of the VBV port 503, the acoustic reactance of the first resonator 504, and / or the percentage open area provided by the perforation pattern.

[0071] In some examples, one of the through-holes 702-720 is implemented as the through-hole 518 based on the target acoustic impedance of the associated resonator (e.g., the first resonator 504). In some examples, the non-through-hole portion of the resonator (e.g., Fig. 6AThe surface area of ​​the first non-perforated portion 620a) of the resonator is selected based on the target acoustic reactance (e.g., resonant frequency) of the resonator. For example, a cross perforation 714 can be implemented in the first resonator 504 to obtain the desired opening area of ​​the perforation 518 in a reduced surface area because these perforation shapes can achieve tighter packing, which in turn allows the frequency associated with the resonator to be slightly lower (because the distance of the perforation from the end (608 or 610) is reduced). Therefore, based on the implementation of Figure 5 and 6A - 6D perforations 518 perforations 702-720, Figure 5 There is a trade-off between the acoustic impedance and the acoustic reactance of the resonator 502. For example, for a nominal 250 Hz resonator, Fig. 6A The first non-perforated portion 620a may cover 50% of the length of the first resonator 602a to produce a resonant frequency of 500 Hz. In another example, the first non-perforated portion 620a may cover 80% of the length of the first resonator 602a to produce a resonant frequency of approximately 315 Hz.

[0072] An example VBV assembly is disclosed herein that includes a VBV port, wherein an acoustic resonator is coupled to a wall of the VBV port. The acoustic resonator includes a wavy and / or corrugated plate that defines a channel or cavity extending in a circumferential direction and a radial direction. Thus, the acoustic resonator can be an arcuate ridge with a variable or consistent (e.g., the same or similar, such as having + / -10%, etc.) internal volume. The example acoustic resonator disclosed herein includes a perforation pattern on one or both sides (e.g., the upstream side or the downstream side) of the ridge relative to the acoustic resonator and / or at the top of the corrugated shape. In some examples, the pattern includes a line, an array, a cross pattern, and / or a triangular pattern of perforations. The internal volume, the number of perforations, and / or the perforation pattern can be adjusted to tune the absorption characteristics of the liner at the desired resonant VBV cavity frequency of interest. In addition, the pattern and / or shape of the perforations (e.g., circular, elliptical, triangular, square, etc.) can be varied to adjust the acoustic impedance characteristics of the acoustic resonator disclosed herein.

[0073] The example acoustic resonators disclosed herein dissipate or dampen acoustic oscillations that propagate to a VBV port in a compressor. Acoustic energy from the resonance of the VBV port may crack, displace, or otherwise damage a stage or component (e.g., rotor blades, stator vanes, rotor blades, etc.) of a supercharger section of the compressor. The disclosed VBV assembly includes an example acoustic suppressor that attenuates the frequencies that dominate the VBV cavity response, thereby mitigating, reducing, or eliminating mechanical excitation of the supercharger section. Thus, the example acoustic liner disclosed herein may attenuate acoustic energy from a resonant VBV port to reduce damage and improve performance of a gas turbine engine.

[0074] Disclosed herein are example methods, devices, systems, and articles for dissipating or dampening acoustic oscillations of VBV components. Further examples and combinations thereof include the following:

[0075] A variable exhaust valve assembly for a gas turbine engine, comprising: a port extending radially outward from a compressor section of the gas turbine engine, the port defining a variable exhaust valve cavity, the port resonating at a resonant frequency based on operating conditions of the gas turbine engine; and an acoustic suppressor positioned on a wall of the port, the acoustic suppressor extending circumferentially along the wall by a length greater than a cross-sectional width of the acoustic suppressor, the acoustic suppressor defining a resonant cavity based on the length and the cross-sectional width, the acoustic suppressor including a perforated portion, the acoustic suppressor being tuned based on the length and the perforated portion to resonate at the resonant frequency.

[0076] A variable exhaust valve assembly according to any preceding clause, wherein the acoustic suppressor is a first acoustic resonator and the resonant cavity is a first resonant cavity, further comprising a second acoustic resonator positioned on the wall adjacent to the first acoustic resonator, the second acoustic resonator comprising a second resonant cavity.

[0077] A variable exhaust valve assembly as in any preceding clause, wherein the first acoustic resonator is coupled to the second acoustic resonator, further comprising a dividing wall positioned between the first resonant cavity and the second resonant cavity.

[0078] A variable exhaust valve assembly according to any preceding clause, wherein said second acoustic resonator extends along a curved length, said length of said first acoustic resonator being different from said curved length.

[0079] A variable exhaust valve assembly according to any preceding clause, wherein the perforated portion of the first acoustic resonator is a first perforated portion positioned along a first dimension, and the second acoustic resonator includes a second perforated portion positioned along a second dimension different from the first dimension.

[0080] A variable exhaust valve assembly as in any preceding clause, wherein the acoustic suppressor is a first acoustic resonator, further comprising a contoured surface defining a plurality of acoustic resonators including the first acoustic resonator.

[0081] A variable exhaust valve assembly as described in any preceding clause, wherein the contoured surface is coupled to the wall of the port.

[0082] A variable exhaust valve assembly according to any preceding clause, wherein the contoured surface and the wall of the port are a single unified component.

[0083] A variable exhaust valve assembly according to any preceding clause, wherein the acoustic suppressor comprises a ridge positioned between a first valley and a second valley, the first valley being upstream of the second valley relative to the exhaust flow path of the port, the perforated portion being positioned between the ridge and the second valley.

[0084] A variable exhaust valve assembly according to any preceding clause, wherein the perforated portion comprises a plurality of circular holes positioned in an array pattern.

[0085] A gas turbine engine comprises: a compressor section; and a variable exhaust valve, the variable exhaust valve comprising: a door, the door being operable between a closed position and an open position; a port, the port having a first wall and a second wall, the first wall and the second wall extending radially outward between the compressor section and the door, the first wall and the second wall defining a cavity and an exhaust flow path between the compressor section and the door; a first plurality of acoustic suppressors, the first plurality of acoustic suppressors being coupled to the first wall; and a second plurality of acoustic suppressors, the second plurality of acoustic suppressors being coupled to the second wall.

[0086] A gas turbine engine as in any preceding clause, wherein the port, the first plurality of acoustic suppressors, and the second plurality of acoustic suppressors extend circumferentially between a first diaphragm and a second diaphragm.

[0087] The gas turbine engine of any preceding clause, wherein the first plurality of acoustic suppressors comprises a first acoustic resonator and a second acoustic resonator, the first acoustic resonator and the second acoustic resonator being tuned to a resonant frequency.

[0088] The gas turbine engine of any preceding clause, wherein the first plurality of acoustic suppressors comprises a first acoustic resonator tuned to a first resonant frequency and a second acoustic resonator tuned to a second resonant frequency different from the first resonant frequency.

[0089] A gas turbine engine according to any preceding clause, wherein the first acoustic resonator comprises a first perforated portion and a first non-perforated portion, and the second acoustic resonator comprises a second perforated portion and a second non-perforated portion, the length of the second non-perforated portion being different from the length of the first non-perforated portion.

[0090] The gas turbine engine of any preceding clause, wherein the first acoustic resonator comprises a first perforation pattern and the second acoustic resonator comprises a second perforation pattern different from the first perforation pattern.

[0091] An aircraft comprises: a gas turbine engine, the gas turbine engine comprising a supercharger section and a high-pressure compressor section; and a variable exhaust valve assembly, the variable exhaust valve assembly being positioned between the supercharger section and the high-pressure compressor section, the variable exhaust valve assembly comprising: a port, the port defining a port of an exhaust flow path; and a first acoustic resonator, the first acoustic resonator being coupled to a wall of the port, the first acoustic resonator comprising a ridge and a plurality of perforations, the ridge defining a resonance cavity.

[0092] An aircraft according to any preceding clause, comprising a contoured surface of the wall coupled to the port, the contoured surface comprising a first valley, a second valley, and a ridge defining the first acoustic resonator, the first valley being positioned downstream of the ridge, and the second valley being positioned upstream of the ridge relative to the exhaust flow path.

[0093] An aircraft as described in any preceding clause, wherein the plurality of perforations are positioned between the ridge and the second valley.

[0094] An aircraft as in any preceding clause, wherein the plurality of perforations is a first plurality of perforations positioned between the first valley and the ridge, further comprising a second plurality of perforations positioned between the ridge and the second valley.

[0095] Although certain example systems, devices, and articles have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all systems, devices, and articles that fully fall within the scope of the claims of this patent.

[0096] The following claims are hereby incorporated into the 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: include: a port extending radially outward from a compressor section of the gas turbine engine, the port defining a variable exhaust valve cavity, the port resonating at a resonant frequency based on operating conditions of the gas turbine engine; and an acoustic suppressor positioned on a wall of the port, the acoustic suppressor extending circumferentially along the wall a length greater than a cross-sectional width of the acoustic suppressor, the acoustic suppressor defining a resonant cavity based on the length and the cross-sectional width, the acoustic suppressor including a perforated portion, the acoustic suppressor being tuned based on the length and the perforated portion to resonate at a resonant frequency.

2. The variable exhaust valve assembly according to claim 1, characterized in that: Wherein the acoustic suppressor is a first acoustic resonator and the resonant cavity is a first resonant cavity, further comprising a second acoustic resonator positioned on the wall adjacent to the first acoustic resonator, the second acoustic resonator comprising a second resonant cavity.

3. The variable exhaust valve assembly according to claim 2, characterized in that: Wherein the first acoustic resonator is coupled to the second acoustic resonator, further comprising a partition wall positioned between the first resonant cavity and the second resonant cavity.

4. The variable exhaust valve assembly according to claim 3, characterized in that: The second acoustic resonator extends along a bending length, and the length of the first acoustic resonator is different from the bending length.

5. The variable exhaust valve assembly according to claim 2, characterized in that: Wherein the perforated portion of the first acoustic resonator is a first perforated portion positioned along a first dimension, and the second acoustic resonator includes a second perforated portion positioned along a second dimension different from the first dimension.

6. The variable exhaust valve assembly according to claim 1, characterized in that: Wherein the acoustic suppressor is a first acoustic resonator, further comprising a contoured surface defining a plurality of acoustic resonators including the first acoustic resonator.

7. The variable exhaust valve assembly according to claim 6, characterized in that: Wherein the contoured surface is coupled to the wall of the port.

8. The variable exhaust valve assembly according to claim 6, characterized in that: Wherein the contoured surface and the wall of the port are a single unified component.

9. The variable exhaust valve assembly according to claim 1, characterized in that: Wherein the acoustic suppressor includes a ridge positioned between a first valley and a second valley, the first valley being upstream of the second valley relative to an exhaust gas flow path of the port, the perforated portion being positioned between the ridge and the second valley.

10. The variable exhaust valve assembly according to claim 9, characterized in that: Wherein the perforated portion comprises a plurality of circular holes positioned in an array pattern.

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