Turbine engine with damper

Abstract

A gas turbine engine has a compressor section for compressing air flowing therethrough to provide a compressed air flow; a combustor including a combustion chamber configured to combust a mixture of a fuel stream and a compressed air stream to produce a combustion product; a turbine section having at least one turbine driven by the combustion products; and a damper in fluid communication with the combustion chamber to attenuate instability in the combustion chamber resulting from combustion products. The damper is defined by the following content: nds < nfp; p is in direct proportion to dpn; and ab < dpv * dpvea, where nds is the number of damper cavities connected in series, nfp is the number of discrete frequencies to be damped, ap is the acoustic damping potential, dpn is the neck opening area ratio, ab is the acoustic damping width, dpv is the damper volume, and dpvea is the damper volume divergence angle.

Description

Technical Field

[0001] This disclosure generally relates to a damper, for example, in a turbine engine. Background Technology

[0002] Turbine engines typically include propellers (e.g., fans or propellers) arranged in fluid communication with each other, and turbocharged engines. A turbocharged engine includes a compressor section, a combustion section, and a turbine section. The combustion section includes combustors for producing combustion products. Attached Figure Description

[0003] Features and advantages will become apparent from the following more specific description of various exemplary embodiments, as illustrated in the accompanying drawings, wherein similar reference numerals generally denote identical, functionally similar, and / or structurally similar elements.

[0004] Figure 1 A schematic cross-sectional view of a turbine engine taken along the longitudinal centerline axis of the engine, according to the present disclosure, is shown.

[0005] Figure 2 The diagram shows a section taken along the longitudinal centerline axis of the engine according to the present disclosure. Figure 1 A schematic cross-sectional view of the burner of a turbine engine.

[0006] Figure 3A The diagram shows a section taken along the longitudinal centerline axis of the engine according to the present disclosure. Figure 2 A schematic cross-sectional view of the damper of the burner.

[0007] Figure 3B The following is shown in accordance with this disclosure: Figure 3A A schematic cross-sectional view of the bottom of the damper.

[0008] Figure 4 The diagram shows a section taken along the longitudinal centerline axis of the engine according to the present disclosure. Figure 2 A schematic cross-sectional view of the damper of the burner.

[0009] Figure 5 The present disclosure shows the method for use Figures 3A-4 A graph showing the damper effectiveness versus frequency.

[0010] Figure 6A The present disclosure shows the method for use Figure 2 A schematic side view of the damper of the burner.

[0011] Figure 6B This shows a section taken along the centerline axis of the damper according to the present disclosure. Figure 6A A schematic cross-sectional view of the damper.

[0012] Figure 7 a plot of damper effectiveness versus frequency for a damper of Figure 6A and Figure 6B a plot of damper effectiveness versus frequency for a damper of DETAILED DESCRIPTION

[0013] The features, advantages, and embodiments of the present disclosure are illustrated or described in or by the following detailed description, drawings, and claims. Moreover, the detailed description is exemplary and explanatory only and is not intended to restrict the scope of the disclosure as claimed.

[0014] Various embodiments of the present disclosure are discussed in detail below. Although specific embodiments are discussed, this is merely for illustrative purposes. Those skilled in the relevant art will recognize that other components and configurations can be used without departing from the present disclosure.

[0015] As used herein, the terms "first" and "second" and the like can be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components.

[0016] The terms "upstream" and "downstream" refer to the relative direction with respect to the flow of fluid in a fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction to which the fluid flows.

[0017] The terms "forward" and "aft" refer to relative positions within a turbine engine or vehicle and refer to the normal operating attitude of the turbine engine or vehicle. For example, for a turbine engine, forward refers to a position closer to the engine inlet, and aft refers to a position closer to the engine nozzle or exhaust.

[0018] As used herein, the terms "low," "mid" (or "medium"), and "high," or their respective comparative forms (e.g., "lower" and "higher," as applicable), when used in conjunction with a compressor, turbine, shaft, fan, or turbine engine component, each refer to relative pressure, relative speed, relative temperature, and / or relative power output within the engine, unless otherwise indicated. For example, a "low power" setting defines an engine configuration to operate at a power output lower than a "high power" setting of the engine, and a "medium power" setting defines an engine configuration to operate at a power output higher than the "low power" setting but lower than the "high power" setting. The terms "low," "mid" (or "medium"), or "high" in the above terms can additionally or alternatively be understood with respect to a minimum allowable speed, pressure, or temperature, or with respect to a minimum or maximum allowable speed, pressure, or temperature of normal, expected, steady-state, or like operation of the engine.

[0019] Unless otherwise specified herein, the terms “connection,” “fixed,” “attached,” “link,” etc., refer to both direct connection, fixation, attachment, or linking, and indirect connection, fixation, attachment, or linking via one or more intermediate components or features. These terms include integral and monolithic configurations (e.g., integral bladed disk rotor blade system).

[0020] Unless the context clearly indicates otherwise, the singular forms “a,” “one,” and “the” include plural references.

[0021] As used herein, the terms "axial" and "axially" refer to a direction and orientation that extends substantially parallel to the centerline of the turbine engine. Furthermore, the terms "radial" and "radially" refer to a direction and orientation that extends substantially perpendicular to the centerline of the turbine engine. Additionally, as used herein, the terms "circumferential" and "circumferentially" refer to a direction and orientation that extends in an arc around the centerline of the turbine engine.

[0022] Scope limitations are combined and interchanged herein, and throughout the specification and claims. Unless the context or language otherwise indicates, these scopes are identified and include all subscopes contained herein. For example, all scopes disclosed herein include endpoints, and endpoints may be combined independently of each other.

[0023] This disclosure provides an acoustic damper for suppressing combustion instability in a combustor. When instability exists in the combustion chamber of a combustor, it manifests as sinusoidal pressure with significant amplitude, which can damage the equipment. Acoustic dampers are used to dampen or reduce instability. The acoustic damper of this disclosure combines a quarter-wavelength tube with a Helmholtz resonator. The damper of this disclosure provides the ability to tailor and enhance acoustic attenuation characteristics to the specific needs of a combustion system. Variations in volume and volume expansion angle allow the damper to capture multi-tone behavior in the combustor and can significantly broaden the attenuation profile. Variations in the neck opening ratio allow for an increase in damping potential. Therefore, even if the tones are independent in the frequency space, the damper of this disclosure can target and dampen multiple frequencies in any combination using a single damper, including targeting and damping low- and high-frequency tones. The damper of this disclosure helps to broaden two or more independent tones. Compared to a quarter-wavelength tube or a Helmholtz resonator, the damper of this disclosure improves combustion dynamics, engine operability, engine durability, and indirectly improves emissions.

[0024] Now refer to the attached diagram, Figure 1 This is a schematic cross-sectional view of the turbine engine 10 taken along the longitudinal centerline axis 12 of the turbine engine 10 according to an embodiment of the present disclosure. Figure 1As shown, the turbine engine 10 defines an axial direction A (extending parallel to a longitudinal centerline axis 12 provided as a reference), a radial direction R orthogonal to the axial direction A, and a circumferential direction C extending about the longitudinal centerline axis 12. Generally, the turbine engine 10 includes a fan section 14 and a turbocharger engine 16 disposed downstream of the fan section 14.

[0025] The turbocharger engine 16 includes, in serial flow relationship, a compressor section 22, a combustion section 28, and a turbine section 30. The turbocharger engine 16 is substantially enclosed by an outer casing 18, which is substantially tubular and defines an annular inlet 20. As Figure 1 As schematically shown, the compressor section 22 includes a booster or low pressure (LP) compressor 24 followed downstream by a high pressure (HP) compressor 26. The combustion section 28 includes a combustor 200 and is located downstream of the compressor section 22. The turbine section 30 is located downstream of the combustion section 28 and includes a high pressure (HP) turbine 32 followed downstream by a low pressure (LP) turbine 34. The turbocharger engine 16 also includes an injection exhaust nozzle section 36 located downstream of the turbine section 30, a high pressure (HP) shaft 38 or spool, and a low pressure (LP) shaft 40. The HP shaft 38 drivingly connects the HP turbine 32 to the HP compressor 26. The HP turbine 32 and the HP compressor 26 are rotationally uniform by the HP shaft 38. The LP shaft 40 drivingly connects the LP turbine 34 to the LP compressor 24. The LP turbine 34 and the LP compressor 24 are rotationally uniform by the LP shaft 40. The compressor section 22, the combustion section 28, the turbine section 30, and the injection exhaust nozzle section 36 together define a core air flowpath.

[0026] For Figure 1 For the depicted embodiment, the fan section 14 includes a fan 42 (e.g., a variable pitch fan) having a plurality of fan blades 44 coupled to a disk 46 in a spaced apart manner. As Figure 1 As shown, the fan blades 44 generally extend outwardly from the disk 46 along the radial direction R. In the case of a variable pitch fan, the plurality of fan blades 44 can be rotated relative to the disk 46 about a pitch axis P by virtue of the fan blades 44 being operably coupled to an actuation member 48 configured to collectively and uniformly change the pitch of the fan blades 44. The fan blades 44, the disk 46, and the actuation member 48 are rotatable together about the longitudinal centerline axis 12 via a fan shaft 50, which is powered by the LP shaft 40 across a power gear box (also referred to as a gear box assembly 52). In this manner, the fan 42 is drivingly coupled to and powered by the turbocharger engine 16, and the turbine engine 10 is an indirect drive engine. The gear box assembly 52 is located between the fan shaft 50 and the LP shaft 40 and is configured to provide a rotational speed differential between the fan shaft 50 and the LP shaft 40. Figure 1The diagram is schematically shown. Gearbox assembly 52 is a reduction gearbox assembly used to regulate the rotational speed of fan shaft 50 when power is transmitted from LP shaft 40 to fan shaft 50, thereby regulating the rotational speed of fan 42 relative to LP shaft 40.

[0027] Still referencing Figure 1 In an exemplary embodiment, the disk 46 is covered by a rotatable fan hub 54 having an aerodynamic profile to facilitate airflow through a plurality of fan blades 44. Furthermore, the fan section 14 includes an annular fan housing or nacelle 56 that circumferentially surrounds at least a portion of the fan 42 and the turbocharged engine 16 via a plurality of outlet guide blades 58 circumferentially spaced around the nacelle 56 and the turbocharged engine 16. Additionally, a downstream section 60 of the nacelle 56 extends above the outer portion of the turbocharged engine 16 and, together with the housing 18, defines a bypass airflow passage 62 therebetween.

[0028] During operation of the turbine engine 10, a volume of air 64 enters the turbine engine 10 through inlet 66 of nacelle 56 or fan section 14. As the volume of air 64 passes through fan blades 44, a first portion of air 68 (also referred to as bypass air 68) is directed into bypass airflow passage 62, and a second portion of air 70 (also referred to as core air 70) is directed into the upstream section of the core air flow path through annular inlet 20 of LP compressor 24. The ratio between bypass air 68 and core air 70 is commonly referred to as the bypass ratio. The pressure of the core air 70 then increases, producing compressed air 72. The compressed air 72 is directed through HP compressor 26 and into combustion section 28, where it is mixed with fuel and ignited to produce combustion gases 74.

[0029] Combustion gas 74 is directed into and expanded in HP turbine 32, where a portion of the thermal and kinetic energy from combustion gas 74 is extracted via one or more stages of HP turbine stator blades 76 and HP turbine rotor blades 78 connected to HP shaft 38. This causes HP shaft 38 to rotate, thereby supporting the operation of HP compressor 26 (self-sustaining cycle). In this way, combustion gas 74 performs work on HP turbine 32. Combustion gas 74 is then directed into and expanded in LP turbine 34. Here, a second portion of thermal and kinetic energy is extracted from combustion gas 74 via one or more stages of LP turbine stator blades 80 and LP turbine rotor blades 82 connected to LP shaft 40. This causes LP shaft 40 to rotate, thereby supporting the operation of LP compressor 24 (self-sustaining cycle) and the rotation of fan 42 via gearbox assembly 52. ​​In this way, combustion gas 74 performs work on LP turbine 34.

[0030] The combustion gases 74 are then directed through the injection exhaust nozzle section 36 of the turbofan engine 16 to provide propulsive thrust. At the same time, the bypass air 68 is directed through the bypass airflow passage 62 before being exhausted from the fan nozzle exhaust section 84 of the turbine engine 10, also providing propulsive thrust. The HP turbine 32, the LP turbine 34, and the injection exhaust nozzle section 36 at least partially define a hot gas path 86 for directing the combustion gases 74 through the turbofan engine 16.

[0031] The turbine engine 10 can be communicatively and operatively coupled along a communication line 102 to an engine controller 100. The engine controller 100 is configured to operate various aspects of the turbine engine 10. The engine controller 100 can be a full authority digital engine control (FADEC). In this embodiment, the engine controller 100 is a computing device having one or more processors 104 and one or more memories 106. The processor 104 can be any suitable processing device, including but not limited to a microprocessor, a microcontroller, an integrated circuit, a logic device, a programmable logic controller (PLC), an application specific integrated circuit (ASIC), and / or a field programmable gate array (FPGA). The memory 106 can include one or more computer-readable media, including but not limited to non-transitory computer-readable media, computer-readable non-volatile media (e.g., flash memory), RAM, ROM, hard drives, flash drives, and / or other memory devices.

[0032] The memory 106 can store information accessible by the processor 104, including computer-readable instructions that can be executed by the processor 104. The instructions can be any set of instructions or sequence of instructions that, when executed by the processor 104, cause the processor 104 and the engine controller 100 to perform operations. In some embodiments, the instructions can be executed by the processor 104 to cause the processor 104 to complete any operations and functions for which the engine controller 100 is configured, as will be further described below. The instructions can be software written in any suitable programming language or can be implemented in hardware. Also, and / or alternatively, the instructions can be executed in logical and / or virtual separate threads on the processor 104. The memory 106 can also store data that is accessible by the processor 104.

[0033] The technology discussed herein relates to computer-based systems and to actions taken by and information sent to and from computer-based systems. Those skilled in the art will recognize that the inherent flexibility of computer-based systems allows for a wide variety of possible configurations, combinations, and divisions of tasks and functionality between and among components. For example, process steps discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, memories, instructions, and applications can be implemented on a single system or distributed across multiple systems. Distributed components can operate sequentially or in parallel.

[0034] The engine controller 100 can be communicatively coupled to one or more sensors employed in the methods of the present disclosure, such as vibration sensors (e.g., accelerometers), temperature sensors, speed sensors, and other sensors within the turbine engine 10. For example, the engine controller 100 can receive data or information from the one or more sensors and optionally store or record the data or information. The engine controller 100 can also control driving of the turbine engine (e.g., rotation of the rotor described in greater detail below).

[0035] Figure 1 The turbine engine 10 depicted in FIG. 1 is by way of example only. In other example embodiments, the turbine engine 10 can have any other suitable configuration. For example, in other example embodiments, the fan 42 can be configured in any other suitable manner (e.g., as a variable-pitch fan or a fixed-pitch fan) and can also be supported using any other suitable fan frame configuration. Further, in other example embodiments, any other suitable number or configuration of compressors, turbines, shafts, or combinations thereof can be provided. In other example embodiments, the engine can also be a direct drive engine that does not have a power gear box (e.g., no gear box assembly 52). The fan speed is the same as the LP shaft speed of the direct drive engine. In still other example embodiments, aspects of the present disclosure can be incorporated into any other suitable turbine engine, such as a turbofan engine, a propfan engine, a turboprop engine, a ductless engine, or a turboshaft engine.

[0036] Figure 2 The longitudinal centerline axis 12( Figure 1The image shows a cross-sectional view of burner 200. Burner 200 has a longitudinal centerline axis 202. Burner 200 includes a burner housing 204 and a burner bushing 206. Burner housing 204 has an outer housing 208 and an inner housing 210, and burner bushing 206 has an outer bushing 212 and an inner bushing 214. Combustion chamber 216 is formed within burner bushing 206. More specifically, outer bushing 212 and inner bushing 214 are disposed between outer housing 208 and inner housing 210. Outer bushing 212 and inner bushing 214 are radially spaced apart from each other, such that combustion chamber 216 is defined therebetween. Outer housing 208 and outer bushing 212 form an outer channel 218 therebetween, and inner housing 210 and inner bushing 214 form an inner channel 220 therebetween. As shown, burner 200 is a single annular burner, but in other embodiments, burner 200 can be any other burner.

[0037] Combustion chamber 216 has a front end 222 (upstream end) and a rear end 224 (downstream end). A swirler / fuel nozzle assembly 226 is positioned at the front end 222 of combustion chamber 216. Swirler / fuel nozzle assembly 226 includes a fuel nozzle 228 and a swirler 230. In an example of an annular burner, such as burner 200, the swirler / fuel nozzle assembly 226 may be positioned around a longitudinal centerline axis 12 (…). Figure 1 One of a plurality of cyclone / fuel nozzle assemblies 226 arranged in a ring configuration in the circumferential direction.

[0038] As discussed above, and with reference to Figure 1 and Figure 2Compressor section 22, combustion section 28 (including combustor 200), and turbine section 30 at least partially form a flow path for core air 70. Core air 70 entering annular inlet 20 is compressed by LP compressor 24 and HP compressor 26 and flows as compressed air stream 236 to combustor 200. Cowl assembly 232 is coupled to upstream ends of outer liner 212 and inner liner 214, respectively. Annular opening 234 formed in cowl assembly 232 enables a first portion 238 of compressed air stream 236 to enter combustor 200. First portion 238 flows through annular opening 234 to support combustion within combustion chamber 216. A second portion 240 of compressed air stream 236 flows around an exterior of combustor liner 206 through outer passage 218 and inner passage 220. Second portion 240 can be introduced into combustion chamber 216 through a plurality of circumferentially spaced dilution holes 242 formed in combustor liner 206 at one or more locations downstream of swirler / fuel nozzle assembly 226. Although a single dilution hole 242 is shown in each of outer liner 212 and inner liner 214, a plurality of dilution holes 242 can be provided in a circumferential direction about longitudinal centerline axis 202. Further, dilution holes 242 can be provided in either outer liner 212 or inner liner 214, or both outer liner 212 and inner liner 214.

[0039] Each swirler / fuel nozzle assembly 226 of the plurality of swirler / fuel nozzle assemblies 226 is coupled to dome plate 244. Each swirler / fuel nozzle assembly 226 receives first portion 238 of compressed air stream 236 from annular opening 234. Swirler 230 of swirler / fuel nozzle assembly 226 creates a turbulent flow in first portion 238. Fuel nozzle 228 injects fuel into the turbulent air flow, and the turbulence facilitates rapid mixing of the fuel with the air. The resulting mixture of fuel and compressed air is discharged into combustion chamber 216 and combusted in combustion chamber 216, producing combustion gases (combustion products) that accelerate as they exit combustion chamber 216. As described in more detail below, damper 250 is disposed within combustor 200.

[0040] Figure 3A and Figure 3B A damper 300 is shown, which can be damper 250 of combustor 200. Figure 2 Damper 300 extends through an opening 301 in outer shell 208 and an opening 303 in outer liner 212 of combustor 200. Although damper 300 is shown extending through opening 301 in outer shell 208, in some examples, damper 300 can be entirely within outer shell 208 such that damper 300 extends only through opening 303 through outer liner 212 and not through outer shell 208. Damper 300 can be an acoustic damper. Figure 2A single damper 300 is shown in FIG. 3. However, the damper 300 can include multiple dampers distributed circumferentially around the combustor 200. Each damper 300 provided extends through a single opening (e.g., opening 303) in the outer liner 212 such that the damper 300 communicates with the combustion chamber 216 through the single opening 303. This allows for multi-octave and wide frequency damping using a single damper and a single opening in the outer liner 212, as described in more detail below.

[0041] Figure 3A and Figure 3B The damper 300 is shown in more detail. The damper 300 includes a damper body 302 having a first damper body portion 302a, a second damper body portion 302b, and a third damper body portion 302c. In some examples, the damper body 302 is a monolithic, one-piece body. The damper 300 includes a damper cavity 304 within the damper body 302. The damper cavity 304 has a varying internal volume defined by a first cavity volume 306 defined by the first damper body portion 302a, a second cavity volume 308 defined by the second damper body portion 302b, and a third cavity volume 310 defined by the third damper body portion 302c. As shown, the damper cavity 304 is a single volume having various cross-sections and shapes as defined by the first cavity volume 306, the second cavity volume 308, and the third cavity volume 310. Figure 3A

[0042] The damper cavity 304 is in fluid communication with the combustion chamber 216 through one or more openings 322 formed in the orifice plate 326, which are also referred to herein as one or more damper necks 322. The one or more openings 322 function as the neck of a Helmholtz resonator. The damper cavity 304 is in fluid communication with the outer passage 218 using one or more openings 324. Figure 2 Figure 1

[0043] ​​​The first damper body portion 302a has a first damper wall 312 that is generally cylindrical in shape such that the first cavity volume 306 is cylindrical. The second damper body portion 302b has a second damper wall 314 that is generally frustoconical in shape such that the second cavity volume 308 is frustoconical. In a radial direction extending outward from the combustor 200, the second damper wall 314 flares from the first damper body portion 302a to the third damper body portion 302c such that the cross-section and volume of the second cavity volume 308 flares from the first cavity volume 306 to the third cavity volume 310. The third damper body portion 302c has a third damper wall 316 that is generally cylindrical in shape such that the third cavity volume 310 is cylindrical.

[0044] The first damper wall axis 318 is parallel to an inner surface of the first damper wall 312. The second damper wall axis 320 is parallel to an inner surface of the second damper wall 314. A damper volume flare angle a is defined between the first damper wall axis 318 and the second damper wall axis 320.

[0045] Figure 4 A damper 400 is shown that can be the damper 250 of the combustor 200. Figure 2 The damper 400 is the same as the damper 300 except for the proportions of the damper body, as described in more detail below. Accordingly, like numbers refer to similar parts as described with respect to the damper 300 Figure 3A ) and alternatives and functions of the damper 300 apply to the damper 400.

[0046] The damper 400 includes a damper body 402 having a first damper body portion 402a, a second damper body portion 402b, and a third damper body portion 402c. In some examples, the damper body 402 is a monolithic, one-piece body. The damper 400 includes a damper cavity 404 within the damper body 402. The damper cavity 404 has a varying internal volume defined by a first cavity volume 306 defined by the first damper body portion 402a, a second cavity volume 408 defined by the second damper body portion 402b, and a third cavity volume 410 defined by the third damper body portion 402c. As shown, the damper cavity 404 is a single volume having various cross-sections and shapes as defined by the first cavity volume 306, the second cavity volume 408, and the third cavity volume 410. Figure 4 The damper cavity 404 is in fluid communication with the combustion chamber 216 Figure 2 ) through the one or more openings 322 and with the outer passage 218 Figure 1 ) with the one or more openings 324.

[0047] The first damper body portion 402a has a first damper wall 312 that is generally cylindrical in shape such that the first cavity volume 306 is cylindrical. The second damper body portion 402b has a second damper wall 414 that is generally frustoconical in shape such that the second cavity volume 408 is frustoconical. In a radial direction extending outward from the combustor 200, the second damper wall 414 gradually expands from the first damper body portion 402a to the third damper body portion 402c such that the cross-section and volume of the second cavity volume 408 gradually expands from the first cavity volume 306 to the third cavity volume 310. The third damper body portion 402c has a third damper wall 416 that is generally cylindrical in shape such that the third cavity volume 410 is cylindrical.

[0048] The first damper wall axis 418 is parallel to an inner surface of the first damper wall 312. The second damper wall axis 420 is parallel to an inner surface of the second damper wall 414. A damper volume expansion angle β is defined between the first damper wall axis 418 and the second damper wall axis 420.

[0049] Both the damper 300 and the damper 400 combine a quarter wavelength tube with a Helmholtz resonator. The first damper body portion 302a, 402a is the quarter wavelength tube. The second damper body portion 302b, 402b and the third damper body portion 302c, 402c together are the Helmholtz resonator. The opening 322 represents the neck of the Helmholtz resonator.

[0050] When an instability is present in the combustion chamber 216( Figure 2 ), the instability manifests as a sinusoidal pressure with a large amplitude that can damage equipment. The dampers 300, 400 attenuate or reduce the instability. The dampers 300, 400 provide the ability to tailor and enhance the acoustic attenuation characteristics within the combustion chamber 216. The dampers 300, 400 allow the damper to capture multi-tonal behavior in the combustion chamber 216 and widen the attenuation curve.

[0051] Comparing aspects of Figure 3A to aspects of Figure 4 , the damper volume expansion angle β of the second damper body portion 402b is smaller than the damper volume expansion angle a of the second damper body portion 302b. The smaller angle results in a smaller cross-section of the second cavity volume 408 (compared to the second cavity volume 308). As a result, the length of the second damper wall 414 is longer than the length of the second damper wall 314. Compared to the damper 300, the damper 400 is smaller in a radial direction (relative to the centerline of the damper) and longer in a longitudinal direction (e.g., parallel to the centerline of the damper). Thus, the damper volume expansion angle affects the volume of the damper.

[0052] Figure 5 Exemplary graphs showing the effect of variable cross-section dampers are shown. Curve 500 shows the damper effectiveness of a damper having a single constant volume (e.g., a quarter wavelength tube). Curve 500 represents a baseline damper effectiveness that is compared to the dampers of curves 502, 504, and 506.

[0053] Curve 502 shows the damper effectiveness of a damper having a single constant volume (e.g., a quarter wavelength tube) that has a larger volume than the damper of curve 500. Greater volume is achieved by increasing the damper volume expansion angle (e.g., the damper volume expansion angle a in Figure 3A the damper of curve 500) and the damper neck (e.g., the diameter of one or more openings 322 in Figure 4 the damper of curve 500) of the damper of curve 500.

[0054] Curve 504 shows the damper effectiveness of a damper having the same volume as the damper of curve 500, where the damper neck (e.g., the diameter of one or more openings 322 in Figure 3B the damper of curve 500) of the damper of curve 500 is changed.

[0055] Curve 506 shows the damper effectiveness of a damper having greater volume (e.g., by increasing the damper volume expansion angle) and damper neck changes (e.g., diameter changes of one or more openings 322) than the damper of curve 500 compared to the damper of curve 500. Curve 506 changes the expansion angle to the same expansion angle as the damper of curve 502 and changes the damper neck to the same size as the damper of curve 504.

[0056] Figure 6A and Figure 6B A damper 600 having a series of damper cavities is shown. That is, the damper 600 has a first damper body 602 and a second damper body 604. The first damper body 602 is connected to the second damper body 604 with a third damper body 606. The first damper body 602 has a first damper cavity 608 and the second damper body 604 has a second damper cavity 612. The third damper body 606 has a third damper cavity 610 that connects the first damper cavity 608 to the second damper cavity 612. The first damper cavity 608 and the second damper cavity 612 are in fluid communication with the combustion chamber 216 Figure 2 ) through one or more openings 614 that act as the neck of the damper 600.

[0057] Figure 7An exemplary graph showing the effect of a series damper cavity is shown. The curve includes two peaks, a first peak 702 and a second peak 704. Each peak represents a frequency damped by one of the damper cavities. For example, the first damper cavity 608 damps a frequency aligned with the first peak 702, and the second damper cavity 612 damps a frequency aligned with the second peak 704.

[0058] The damper of the present disclosure demonstrates a direct proportional relationship between the number of cavities in series and the number of discrete frequencies (also referred to as tones) damped or attenuated. This can be effectively written as:

[0059] n ds ∝n fp

[0060] where n ds is the number of damper cavities in series, and n fp is the number of discrete frequencies (tones) damped or attenuated. The damper cavities n ds may be one volume to four volumes, and thus, the target frequencies n fp may also be one frequency to four frequencies. In one example, the damper cavities n ds may be one volume to two volumes, and thus, the target frequencies n fp may also be one frequency to two frequencies.

[0061] Further, there is a direct proportional relationship between the acoustic damping potential (also referred to as the growth rate reduction or acoustic decay potential) and the neck opening area ratio. This can be effectively written as:

[0062] a p ∝dp n

[0063] where a p is the acoustic damping potential (i.e., the potential growth rate reduction or acoustic decay at each frequency), and dp n is the damper parameter of the neck opening area ratio. Referring briefly to Figure 3B , the neck opening area ratio represents the ratio of the total area of the damper neck 322 to the total area of the orifice plate 326 (including the area of the damper neck 322, i.e., the area of the plate and the area of the opening). The acoustic damping potential a p may be zero rad / sec to one thousand rad / sec, and the neck opening area ratio dp n may be 0 to 1. In an example, the acoustic damping potential a p may be zero rad / sec to two hundred fifty rad / sec. In an example, the neck opening area ratio dp n may be 0.1 to 1.

[0064] Further, there is a direct proportional relationship between the acoustic damping width and the product of the damper volume and the damper volume expansion angle. This can be effectively written as:

[0065] a b ∝ dp v * dp vea

[0066] where a b is the acoustic damping width (i.e., the width of the frequency range over which the damper is effective), dp v is the damper parameter of the damper volume, and dp vea is the damper parameter of the damper volume expansion angle. The acoustic damping potential a b may be zero hertz to five thousand hertz. The damper volume may be 0.05 cubic inches to 50 cubic inches. The damper volume expansion angle dp vea may be zero degrees to ninety degrees. In examples, the acoustic damping potential a b may be zero hertz to five hundred hertz. In examples, the acoustic damping potential a b may be zero hertz to fifty hertz. In examples, the damper volume expansion angle dp vea may be zero degrees to thirty degrees. All three of the above relationships contribute to the effectiveness of the damper and are used to form a damper that provides the desired damping magnitude and broadening. In designing a damper, the damper size must also be considered in conjunction with the above relationships. In some examples, the width of the damper is limited. For example, if the width of the damper is too large, the damper can interfere with other components of the turbine engine. Thus, a tradeoff between acoustic performance and impact on surrounding hardware is also considered to optimize performance given the geometric constraints.

[0067] Referring back to Figure 5 , the x-axis shows the width of the frequencies over which the damper is effective (e.g., a b ). For example, the more frequencies that the curve covers, the wider the damping. The y-axis represents the damping potential of the damper (e.g., a p ). For example, the higher the curve is along the y-axis, the greater the damping potential. As Figure 5 shown, the damper volume expansion angle dp vea and the damper volume dp v have a direct impact on the broadening of the damping (e.g., compare the width of curve 502 to the width of curve 500). The neck opening area ratio (e.g., dp n ) has a direct impact on the damping potential (e.g., compare the magnitude of curve 504 to the magnitude of curve 500). By adjusting all three parameters (e.g., dp vea , dp v , and dpn ), as shown by curve 506, both the magnitude and width of the damper are improved (compared to curve 500).

[0068] Accordingly, the damper of the present disclosure provides improved acoustic damper performance by having two or more dampers in series, having a damper with a design that combines a quarter- wavelength tube design with a Helmholtz resonator design, or a combination thereof. Accordingly, the damper of the present disclosure improves the damping effect over a wide frequency range.

[0069] Further aspects are provided by the subject matter of the following clauses.

[0070] A gas turbine engine comprising: a compressor section to compress air flowing therethrough to provide a compressed air flow; a combustor comprising a combustion chamber configured to combust a mixture of a fuel flow and the compressed air flow to produce combustion products; a turbine section having at least one turbine driven by the combustion products; and a damper in fluid communication with the combustion chamber to attenuate instabilities in the combustion chamber produced by the combustion products, the damper defined by: n ds ∝n fp ; a p ∝dp n ; and a b ∝dp v *dp vea , where n ds is a number of damper cavities in series, n fp is a number of discrete frequencies to damp, a p is an acoustic damping potential, dp n is a neck opening area ratio, a b is an acoustic damping width, dp v is a damper volume, and dp vea is a damper volume expansion angle.

[0071] The gas turbine engine of any preceding clause, wherein the damper has a damper body that is at least partially conical.

[0072] The gas turbine engine of any preceding clause, wherein the damper comprises a single damper volume.

[0073] The gas turbine engine of any preceding clause, wherein the damper comprises a plurality of damper volumes fluidically coupled together in series.

[0074] The gas turbine engine of any preceding paragraph, wherein the neck opening area ratio is a ratio of a total area of a damper neck to a total area of an orifice plate, the total area of the orifice plate including the area of the damper neck.

[0075] The gas turbine engine of any preceding paragraph, wherein the damper volume is 0.05 cubic inches to 50 cubic inches.

[0076] The gas turbine engine of any preceding paragraph, wherein the neck opening area ratio is 0.01 to 1.

[0077] The gas turbine engine of any preceding paragraph, wherein the number of damper cavities in series is one volume to four volumes.

[0078] The gas turbine engine of any preceding paragraph, wherein the number of damper cavities is one volume to two volumes.

[0079] The gas turbine engine of any preceding paragraph, wherein the number of discrete frequencies to be damped is one frequency to four frequencies.

[0080] The gas turbine engine of any preceding paragraph, wherein the number of discrete frequencies to be damped is one frequency to two frequencies.

[0081] The gas turbine engine of any preceding paragraph, wherein the acoustic damping potential is zero rad / sec to one thousand rad / sec.

[0082] The gas turbine engine of any preceding paragraph, wherein the acoustic damping potential is zero rad / sec to two hundred fifty rad / sec.

[0083] The gas turbine engine of any preceding paragraph, wherein the acoustic damping width is zero hertz to five thousand hertz.

[0084] The gas turbine engine of any preceding paragraph, wherein the acoustic damping width is zero hertz to fifty hertz.

[0085] The gas turbine engine of any preceding paragraph, wherein the damper volume expansion angle is zero degrees to ninety degrees.

[0086] The gas turbine engine of any preceding paragraph, wherein the damper volume expansion angle is zero degrees to thirty degrees.

[0087] The gas turbine engine of any preceding paragraph, wherein the damper is coupled to an outer liner of the combustor through a single opening in the outer liner.

[0088] The gas turbine engine of any preceding paragraph, wherein the damper is one of a plurality of dampers disposed circumferentially about the combustor.

[0089] The gas turbine engine of any preceding paragraph, wherein each of the plurality of dampers is identical.

[0090] The gas turbine engine of any preceding paragraph, wherein each of the plurality of damper volumes is aimed at a different frequency to be damped.

[0091] The gas turbine engine of any preceding paragraph, wherein the combustor is defined by a combustion liner, the gas turbine engine further comprising an outer casing surrounding the combustion liner.

[0092] The gas turbine engine of any preceding paragraph, wherein each of the combustion liner and the casing comprises an opening therethrough, and the damper extends through the opening in each of the combustion liner and the casing.

[0093] The gas turbine engine of any preceding paragraph, wherein the combustion liner comprises an opening therethrough, and the damper is located entirely within the outer casing such that the damper extends only through the opening of the combustion liner and not through the outer casing.

[0094] The gas turbine engine of any preceding paragraph, wherein the damper extends through a single opening in the combustion liner.

[0095] A gas turbine engine comprising: a compressor section for compressing air flowing therethrough to provide a compressed air flow; a combustor comprising a combustion chamber configured to combust a mixture of a fuel flow and the compressed air flow to produce a combustion product; a turbine section having at least one turbine driven by the combustion product; and a damper in fluid communication with the combustion chamber to attenuate instabilities in the combustion chamber produced by the combustion product, the damper defined by n ds ∝n fp wherein n ds is the number of damper cavities in series, and n fp is the number of discrete frequencies to be damped.

[0096] The gas turbine engine of any preceding paragraph, the damper further defined by a p ∝dp n wherein a p is an acoustic damping potential, and dp n is a neck opening area ratio.

[0097] The gas turbine engine of any preceding paragraph, the damper further defined by a b ∝dp v *dp vea defined, where a b is an acoustic damping width, dp v is a damper volume, and dp vea is a damper volume expansion angle.

[0098] A gas turbine engine comprising: a compressor section to compress air flowing therethrough to provide a compressed air flow; a combustor comprising a combustion chamber configured to combust a mixture of a fuel flow and the compressed air flow to produce combustion products; a turbine section having at least one turbine driven by the combustion products; and a damper in fluid communication with the combustion chamber to attenuate instabilities in the combustion chamber produced by the combustion products, the damper further defined by a p ∝dp n defined, where a p is an acoustic damping potential, and dp n is a neck opening area ratio.

[0099] The gas turbine engine of any preceding paragraph, the damper further defined by a b ∝dp v *dp vea defined, where a b is an acoustic damping width, dp v is a damper volume, and dp vea is a damper volume expansion angle.

[0100] The gas turbine engine of any preceding paragraph, the damper further defined by n ds ∝n fp defined, where n ds is a number of damper cavities in series, and n fp is a number of discrete frequencies to damp.

[0101] A gas turbine engine comprising: a compressor section to compress air flowing therethrough to provide a compressed air flow; a combustor comprising a combustion chamber configured to combust a mixture of a fuel flow and the compressed air flow to produce combustion products; a turbine section having at least one turbine driven by the combustion products; and a damper in fluid communication with the combustion chamber to attenuate instabilities in the combustion chamber produced by the combustion products, the damper further defined by a b ∝dpv dp vea is defined by a b is the acoustic damping width, dp v is the damper volume, and dp vea is the damper volume expansion angle.

[0102] The gas turbine engine of any preceding paragraph, the damper is further defined by a p dp n is defined by a p is the acoustic damping potential, and dp n is the neck opening area ratio.

[0103] The gas turbine engine of any preceding paragraph, the damper is further defined by n ds n fp is defined by n ds is the number of damper cavities in series, and n fp is the number of discrete frequencies to damp.

[0104] While the foregoing description has been directed to the preferred embodiments of the present disclosure, other variations and modifications will be apparent to those skilled in the art and can be made without departing from the disclosure. Furthermore, features described in conjunction with one embodiment can be used with other embodiments, even if such features are not explicitly stated in such combination.

Claims

1. A gas turbine engine, characterized in that, include: A compressor section for compressing air flowing through it to provide a compressed air flow; A burner, the burner including a combustion chamber configured to burn a mixture of a fuel stream and a compressed air stream to produce combustion products; A turbine section having at least one turbine driven by the combustion products; and A damper, in fluid communication with the combustion chamber, for attenuating instability in the combustion chamber caused by the combustion products, the damper being defined by the following: n ds ∝n fp ; a p ∝dp n ;and a b ∝dp v *dp vea , Where, n ds n is the number of damper cavities connected in series. fp The number of discrete frequencies to be damped, a p It is the acoustic damping potential, dp n It is the ratio of the neck opening area, a b It is the acoustic damping width, dp v It is the damper volume, and dp vea It is the damper volume expansion angle.

2. The gas turbine engine according to claim 1, characterized in that, The damper has a damper body that is at least partially conical.

3. The gas turbine engine according to claim 1, characterized in that, The damper described therein comprises a single damper volume.

4. The gas turbine engine according to claim 1, characterized in that, The damper comprises multiple damper volumes that are fluidly connected in series.

5. The gas turbine engine according to claim 1, characterized in that, The neck opening area ratio is the ratio of the total area of ​​the damper neck to the total area of ​​the orifice plate, wherein the total area of ​​the orifice plate includes the area of ​​the damper neck.

6. The gas turbine engine according to claim 1, characterized in that, The damper has a volume of 0.05 cubic inches to 50 cubic inches.

7. The gas turbine engine according to claim 1, characterized in that, The neck opening area ratio is 0.01 to 1.

8. The gas turbine engine according to claim 1, characterized in that, The number of damper cavities connected in series ranges from one to four volumes.

9. The gas turbine engine according to claim 8, characterized in that, The number of damper cavities is one to two volumes.

10. The gas turbine engine according to claim 1, characterized in that, The number of discrete frequencies to be damped is one to four frequencies.

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