Abstract: In a combustor (1) for a gas turbine, the combustor (1) includes a burner system (2) and a fuel supply system (3). The burner system (2) includes at least two burner groups (A, B) each with at least one burner (5). The fuel supply system (3) includes a main line (7), which is connected to a fuel source (8), and also an auxiliary line (9) for each burner group (A, B). Each auxiliary line (9) is connected to each burner (5) of the associated burner group (A, B) and is connected to the main line (7) by a controllable distribution valve (10). A sensing system (11) measures pressure pulsation values and/or emission values for each burner group (A, B). A control system (12), in dependence upon the pulsation values and/or the emission values, controls the distribution valves (10) so that in each burner group (A, B) the pulsation values and/or the emission values assume and/or fall below predetermined threshold values.

Abstract: An embodiment of the technology described herein is an auxiliary power unit assembly. The auxiliary power unit assembly includes an auxiliary power unit being installable in an aircraft having a cabin, a duct connecting the cabin and the auxiliary power unit, and a noise reduction feature in the duct.

Abstract: Under certain conditions, the fuel delivery system can contribute to the formation of strong dynamic pressures in the combustor of a turbine engine. Embodiments of the invention provide a system for dynamically stiffening the fuel supply passage to suppress damaging combustion dynamics. To that end, a Helmholtz resonator can be placed along and in branched relation to the fuel supply passage. The resonator can produce the effect of adding a pressure release opening at a selected location in the fuel line, causing a shift in the fuel line pressure wave pattern that blocks fuel flow fluctuations at the outlet of the fuel passage at the frequency of the oscillation. The pressure wave shift results in a shifting of the volume velocity wave pattern. Ideally, the resonator can be positioned along the flow path such that the volume velocity of the fuel at the fuel passage exit is minimized.

Abstract: Aspects of the invention are directed to a system for improving the damping performance of an acoustic resonator. According to aspects of the invention, a resonator, such as a Helmholtz resonator, can be attached to a surface of a combustor component in a turbine engine. The combustor component includes a region in which a plurality of passages extend through the thickness of the component. The resonator is attached to the component so as to enclose at least some of the passages. The passages are in fluid communication with a cavity defined between the component surface and the resonator. Resonator performance is a function of the length of the passages in the component. According to aspects of the invention, resonator performance can be improved by reducing the length of the passages in the component by reducing the thickness of the component in a region that includes the plurality of passages.

Abstract: A noise control cassette for a gas turbine engine includes a perforated face sheet configured for exposure to an airflow, a non-perforated backing sheet, a core arranged between the face sheet and the backing sheet and defining a cavity between the face sheet and the backing sheet having an effective length tuned so as to provide acoustic reactance control, and an attachment face for attaching the cassette to an airfoil-shaped structure.

Abstract: A combustion chamber suitable for a gas turbine engine is provided with at least one Helmholtz resonator having a resonator cavity and a resonator neck in flow communication with the chamber interior. The resonator neck is provided with at least cooling holes extending through its wall for improved damping and cooling, at least one of the holes is directed towards the resonator cavity.

Abstract: Device for damping oscillations of a combustion chamber that includes at least one resonator connected to a pre-chamber in a vibration-damping manner. The pre-chamber is connected to a combustion chamber in a vibration-damping manner via at least one passage channel. This abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

Abstract: A premix burner has a swirl generator and two perforated through flow elements are arranged at a defined distance from one another in the inflow region for the combustion air. The through flow elements are preferably arranged in such a way that substantially the entire combustion airstream has to flow through the through flow elements. The degree of perforation of the through flow elements and the distance between these elements are preferably adapted to one another in such a way that a reflection free condition for combustion pulsation frequencies which may be expected is present at the exit from the burner into the combustion chamber.

Abstract: A system for damping thermo-acoustic instability in a combustor device for a gas turbine, the combustor device including at least one combustion chamber, in particular of an annular type, and at least one burner associated to the combustion chamber and mounted in a position corresponding to a front portion set upstream of the combustion chamber; the damping system including at least one Helmholtz resonator including a casing defining inside it a pre-set volume and a neck for hydraulic connection between the pre-set volume and the combustion chamber, the neck being connected to one side of the combustion chamber at a distance from the front upstream portion thereof provided with the at least one burner. The casing of the resonator includes structure which varies the pre-set volume within a pre-set range and structure which delivers a cooling fluid.

Abstract: A system for preventing the onset, or mitigating the effect, of thermoacoustic instability in an annular combustor of a premixed combustion gas turbine. A plenum of walls is oriented in a meridian direction so as to obstruct circulation of tangential flows inside the combustor. These walls are desirably situated in suitable azimuthal positions so as to cancel the onset of any standing oscillation mode. In this manner, the walls preferably divide the space in the combustor formed by the plenum asymmetrically. Thus, the resulting annular volumes may extend desirably along selected azimuthal sectors whose angular widths are not multiples of one another.

Abstract: A device for turbocharging an internal combustion engine including a turbocompessor including a turbine driven by the engine exhaust gas and a compressor driven by the turbine and compresses the engine intake air. An air intake conduit connects the compressor output to an air intake manifold to the engine and includes a chamber for damping pulsations generated at the compressor output. The damping chamber is connected directly to the compressor output.

Abstract: The present invention provides an adaptive combustion controller and method for a turbine engine. The adaptive combustion controller and method modulates the fuel flow to the turbine engine combustor to reduce combustion instabilities. In particular, the adaptive combustion controller includes a fuel flow phase controller and a fuel flow magnitude controller. The adaptive combustion controller receives sensor data from the turbine engine. In response to the sensor data the fuel flow phase controller adjusts the phase of the modulated fuel flow to reduce instabilities in the combustor. Likewise, in response to the sensor data the fuel flow magnitude controller adjusts the magnitude of the modulated fuel flow to further reduce the instabilities in the combustor. By modulating the fuel flow to the combustor, and adaptively adjusting the phase and magnitude of the modulated fuel flow, the adaptive combustion controller is able to effectively reduce combustion instabilities.

Abstract: A combustion chamber according to the invention, in particular for a gas turbine, includes at least one combustion chamber wall through which cooling fluid flows and at least one resonator device. The combustion chamber according to the invention is distinguished in that the resonator device is integrated into the combustion chamber wall in such a way that it has the cooling fluid flow passing there through.

Abstract: One or more Helmholtz-type resonators (270) is/are provided at the junction (260) of a combustor (220) and a combustion chamber (240) of a gas turbine engine (100). In one embodiment, adjacent Helmholtz-type resonators (290, 291, 292), which may be separated by respective baffles (285), have different volumes that help provide for damping different undesired combustion-generated acoustic pressure waves. In some embodiments, a structural member (435) may be provided between adjacent Helmholtz-type resonators (425, 426, 427, 428) at the junction. At least one of the plurality of Helmholtz-type resonators comprises one or more inlet openings (480), and one or more exit openings (482). Embodiments (370, 425-429) are described in which Helmholtz-type resonators provided at the junction are enlarged in size using various approaches.

Abstract: At least one Helmholtz damper is arranged at a combustion chamber for a gas turbine in order to damp thermoacoustic oscillations; the damping volume of this Helmholtz damper is in communication with the combustion chamber via a connecting passage. Optimum damping is achieved in a simple way by virtue of the Helmholtz damper being designed in such a manner that its damping frequency is adjustable.

Abstract: An acoustic resonator for use in an engine is provided. The acoustic resonator includes a cavity having a volume, an aperture, and a passage connecting the aperture and the cavity. The aperture has a profiled surface for delaying separation of fluid entering the passage and for reducing losses caused by fluid separation.

Abstract: This invention relates to a burner, especially a gas turbine burner, wherein a Helmholtz resonator downstream of a fuel inlet position in directly linked with a burner channel. In this manner, combustion oscillations do not arrive at the fuel inlet position, thereby reducing acoustic disturbances and air ration deviations which are the main cause for the formation of combined oscillations. The invention also relates to a method for operating a burner and a gas turbine.

Abstract: A gas-turbine combustion chamber wall for a lean-burning gas-turbine combustion chamber with a combustion chamber casing 2, 3 and several combustion chamber segments arranged in the combustion chamber casing 2, 3 and forming a combustion chamber wall 10. Each of the combustion chamber segments is supplied with cooling air with film cooling via axial and/or radial cooling holes 16, 17, with the cooling holes 16, 17 being axially spaced from each other and with dampening openings 19a being provided in this area for the introduction of cooling air.

Abstract: A method for operating a gas turbine engine includes coupling an anti-resonant frequency system to a combustor including a premixer assembly and a plurality of damper tubes, and adjusting the anti-resonant frequency system until the anti-resonant frequency of the damper tubes is approximately equal to the combustor resonant frequency.

Abstract: Integrated axially varying engine mufflers, and associated methods and systems. An arrangement in accordance with one embodiment of the invention includes a tailcone having a tapering external surface, a cavity disposed within the surface, and an engine muffler disposed within the cavity. The engine muffler can have a tapering outer surface, a porous inner surface disposed inwardly from the outer surface, and a plurality of cells disposed between the outer surface and the inner surface in fluid communication with the perforations of the inner surface. The inner surface can be positioned adjacent to an exhaust gas flow path having an entrance aperture and an exit aperture. Cells positioned toward the entrance aperture can have a first dimension extending away from the gas path, and cells positioned toward the exit aperture can have a second, different, dimension extending away from the exhaust gas path.

Abstract: The invention relates to a gas turbine comprising a combustor that extends into a combustion chamber. The port of the combustor is surrounded in a ring-shaped manner by a Helmholtz resonator, whereby combustion oscillations are effectively suppressed due to close contact with the flame while irregularities in temperature are prevented.

Abstract: A method and device for decoupling combustor attenuation and pressure fluctuation from turbine attenuation and pressure fluctuation in a gas turbine engine. The engine has: a compressor; a combustor; and a turbine, that generate a flow of hot gas from the combustor to the turbine. An aerodynamic trip is disposed in at least one of; a combustor wall; and an inner shroud of the nozzle guide vane ring, and is adapted to emit jets of compressed air from cross flow ports into the flow of hot gas from the combustor. The air jets from the cross flow ports increase turbulence and equalize temperature distribution in addition to decoupling the attenuation and pressure fluctuations between the combustor and the turbine.

Abstract: The present invention relates to a method and a device (1) for affecting thermoacoustic oscillations in a combustion system (6) comprising at least one burner (7) and at least one combustor (8). In order to improve the action of affecting the thermoacoustic oscillations, a gas flow forming in the e region of the burner (7) is excited acoustically, modulated injection of fuel is carried out, the acoustic excitation of the gas flow and the modulated injection of the fuel are coordinated in order to affect the same interference frequency.

Abstract: A resonator for damping pressure waves or instabilities in a system supported by acoustic energy wherein the resonator adopts the use of counter-bored openings on the downstream side of the resonator within the flow path of the system. The resonator includes a first member and a second member where the second member includes a plurality of openings therethrough with each hole having a counter-bore on its upstream side. The first member has a size substantially smaller than the diameter of said flow path and a first plurality of openings therethrough. The openings are in fluid communication with the flow path. The second member has a size generally equal to the first member and a second plurality of openings therethrough, which openings are in fluid communication with the flow path.

Abstract: A passive acoustic liner system (50) for attenuating a sound field comprising, in acoustic series, a mode-scattering segment (48) and a sound-absorbing segment (40), wherein the mode scattering segment (48) provides a reactance between ?12 and ?2 ?c and the sound absorbing segment (40) provides a reactance between ?1 and 0 ?c thereby providing a reactance discontinuity such that mode-scattering of the sound field enables the sound-absorbing segment (48) to further absorb the scattered sound.

Abstract: A system for reducing jet noise emission from an internally mixed gas turbine engine exhaust, comprising a fan/core flow mixer having a plurality of mixer lobes and a common flow nozzle having an equal number of tabs located along a circumferential edge of an aft end of the nozzle. There is a predetermined clocking relationship between the plurality of mixer lobes and the plurality of nozzle tabs that results in reduced exhaust noise emission, most evident in the lower frequency range. A method for reducing jet noise emission from an internally mixed gas turbine engine exhaust comprises selectively aligning a circumferential distribution of a mixed flow vorticity field produced by a fan/core mixer with a circumferentially distributed exhaust flow vorticity field produced by a modified common flow nozzle at an exit plane of the engine exhaust.

Abstract: A description is given of a damping arrangement for reducing resonant vibrations in a combustion chamber (1), with a combustion-chamber wall (2), which is of double-walled design and, with an outer wall-surface part (22) and an inner wall-surface part (21) facing the combustion chamber (1), gastightly encloses an intermediate space (3), into which cooling air can be fed for purposes of convective cooling of the combustion-chamber wall (2). The invention is distinguished by the fact that at least one third wall-surface part (4) is provided, which, with the outer wall-surface part (22), encloses a gastight volume (5), and that the gastight volume (5) is connected gastightly to the combustion chamber (1) by at least one connecting line (6).

Abstract: A gas turbine combustor includes a combustion liner in which a combustion region is formed; and a housing provided for a wall of the combustion liner in a predetermined circumferential region of the combustion liner to form a resonance space between the combustion liner and the housing. The combustion region and the resonance space are connected by a plurality of combustion liner through-holes, and a circumferential length of the housing is longer than a diameter of the combustion liner.

Abstract: Aspects of the invention relate to resonator assemblies for use in non-uniform flow environments. The resonator assemblies include one or more features, such as a box or a scoop, for substantially equalizing the pressure on the resonator. In the box configuration, a box is attached on top of the resonator. The box has a top plate with a plurality of openings and at least one side wall extending from the entire periphery of the top plate. A plenum is defined between the box and the resonator plate. In the scoop configuration, a scoop is attached to the top of the resonator such that the scoop substantially overhangs the resonator. The scoop includes at least one side wall extending substantially perpendicularly therefrom, except for one side without a side wall so as to provide an opening into a space defined between the scoop and the resonator.

Abstract: A combustion chamber suitable for a gas turbine engine is provided with at least one Helmholtz resonator having a resonator cavity and a damping tube in flow communication with the chamber interior. The damping tube is provided with at least one cooling hole extending through its wall for improved damping and cooling.

Abstract: Combustion driven pressure pulsations may limit the range of operating conditions where a modern gas turbine can operate with low emission and high efficiency performance. The control of acoustic vibrations has been consequently growing as an essential issue in gas turbine design, development and maintenance. The basic idea of the present invention is to use cooling air leakage through the gaps (7) of combustor liner segments (3;4) to get acoustic damping of combustion pulsations. The main component of the design is the sealing device (8) which covers the gap (7) between the two liner segments (3) and (4). The sealing device (8) collects in the plenum (9) some of the cooling air (6) flowing between the outer casing (1) and the inner liner structure (2). For this purpose the sealing device (8) is provided with openings (12) along the side walls (10) which allow the cooling air (6) to enter the plenum (9).

Abstract: A method of reducing engine noise generation by decoupling: acoustic and hydrodynamic fluctuation generated by a compressor and a fuel supply system; from acoustic and hydrodynamic fluctuation of a combustor, by: deflecting fuel jets into a fuel nozzle mixing chamber in a number of counter-rotating adjacent pairs of fuel laden vortices; emitting a resulting fuel-air mixture into the combustor downstream from the fuel nozzle mixing chamber.

Abstract: An engine includes at least one pulse detonation chamber configured to receive and detonate a fuel and an oxidizer. The pulse detonation chamber has an outlet end and includes a porous liner adapted to fit within an inner surface of the pulse detonation chamber within a vicinity of the outlet end. The engine also includes a casing housing the pulse detonation chamber.

Abstract: Arrangement at a gas turbine installation for the generating of electricity, where inlet air filter housing, bleed air outlet and inlet for the vent air to the turbine housing are integrated into two units, an upper filter housing and a lower intermediate housing connected to the turbine housing. The lower intermediate housing includes a silencer for the inlet air that at the same time connects the filter housing with the turbine inlet. The compressor bleed air system is divided into two parts, one in the intermediate housing and one extending through the filter housing. The vent air for the turbine housing is drawn in through an end wall of the filter housing and down into the turbine housing through separate spaces surrounding the compressor bleed ducting in the filter and intermediate housings.

Abstract: The invention relates to a burner apparatus (1) for burning fuel (5) with air (4) to combustion gas, in particular within a combustion turbine, comprising a premixing chamber (3) for premixing fuel (5) and air (4) with. The premixing chamber (3) having an air inlet (8) for air (4) to enter said premixing chamber (3), a fuel inlet (11) for a gaseous or liquid fuel (5) to enter said premixing chamber (3), and an outlet (12) for a mixture of air (4) an fuel (5) wherein, the fuel inlet (11) being located between said air inlet (8) and said outlet (12). The burner apparatus (1) Further comprises at least one air blocking member (2) situated at the air inlet (8) for stabilising a burner premixing flame by locally blocking the flow of air (4) entering said premixing chamber (3) so that downstream said outlet (12) a locally inhomogeneous fuel concentration (23) results generating a locally hot stream of combustion gas being hotter than the average flame temperature.

Abstract: An augmentor system minimizes acoustic pressure fluctuations on the heat release process within the augmentor by staggering the vanes therein. The alternating axial vane stagger pattern arranges the downstream set of vanes as baffles which prevent the propagation of tangential acoustic waves between the vanes to protect the upstream set of vanes from the effects of transverse acoustic velocity fluctuations which minimizes screech without substantially affecting augmentor performance.

Abstract: A combustor structure of a gas turbine, in which a sheet-like vibration damper, which resonates with the air vibration in the intake chamber and absorbs the energy of the air vibration, is attached to the inner wall of the casing by an attaching member via a space. The sheet-like vibration damper is made of a single-layered thin flat plate or multi-layered thin flat plates. In case of the multi-layered thin flat plate, the air vibration energy in the intake chamber is absorbed not only by resonance but also by friction among the multi-layered thin plates. The sheet-like vibration damper may be made of a three-dimensional profile member having an inner space in which the attaching member is housed. If the thin flat plates are used, the surface areas thereof are not identical. If the three-dimensional profile members are used, the volumes of the inner spaces are not identical. Consequently, the sheet-like vibration damper can absorb and attenuate the vibration energy of different frequencies.

Abstract: A multi-axial pivoting liner within the combustion system of a turbine engine allows the system to work with minimum thermal interference, especially during system operation at transient conditions, by allowing the liner to pivot and slide about its centerline and relative to the turbine scroll. The pivoting liner has the ability to control and minimize air leakage from part to part, for example, from the liner to the turbine scroll and liner to the surrounding structures, during various operating conditions. Additionally, the liner provides for easy assembly with no flow path steps. Finally, the pivoting liner tolerates thermal and mechanical stresses and minimizes thermal wear.

Abstract: A gas turbine includes an annular combustion chamber and an outer wall of an annular combustion chamber. A straining ring is arranged on the outer wall of the annular combustion chamber and enables oscillations of the outer wall to be damped via friction. The effects of combustion oscillations produced by damaging vibrations of the annular combustion chamber are thus reduced. A method is further for damping an oscillation of an outer wall of an annular combustion chamber.

Abstract: A method of operating a gas turbine combustion system having reduced emissions and improved flame stability at multiple load conditions is disclosed. The improved combustion system accomplishes this through complete premixing, a plurality of fuel injector locations, combustor geometry, and precise three dimensional staging between fuel injectors. Axial, radial, and circumferential fuel staging is utilized including fuel injection proximate air swirlers. Furthermore, strong recirculation zones are established proximate the introduction of fuel and air premixture from different stages to the combustion zone. Fuel injection staging sequences are disclosed that create the conditions necessary to provide stable combustion and reduced emissions at multiple load conditions.

Abstract: A reheat combustion system for a gas turbine comprises a mixing tube adapted to be fed by products of a primary combustion zone of the gas turbine and by fuel injected by a lance; a combustion chamber fed by the said mixing tube; and at least one perforated acoustic screen. The or each said acoustic screen is provided inside the mixing tube or the combustion chamber, at a position where it faces, but is spaced from, a perforated wall thereof. In use, the perforated wall experiences impingement cooling as it admits air into the combustion system for onward passage through the perforations of the said acoustic screen, and the acoustic screen damps acoustic pulsations in the mixing tube and combustion chamber.

Abstract: Methods and apparatus for operating a gas turbine engine without sustained detrimental levels of dynamic pressure are provided. The engine includes a combustor. The method includes determining the combustor acoustic level amplitude, comparing the acoustic level to a predetermined upper acoustic limit, and adjusting a fuel flow distribution to the combustor using a closed loop controller to facilitate reducing the acoustic level to a predetermined lower acoustic limit that is less than the upper acoustic limit.

Abstract: For the purpose of reduced NOx gas emission, a gas turbine engine comprises a cylinder having a combustion region inside of the cylinder; a resonator having a cavity and provided around the surface of the cylinder and sound absorption holes formed on the cylinder and having opening ends on the cylinder.

Abstract: A gas turbine engine combustor defining a combustion zone therein and being adapted for receiving compressed air from a compressor. The combustor comprises inner and outer walls spaced-apart by a predetermined spacing distance and defines a cavity therebetween. The outer wall has a first area defining at least an impingement aperture therein, the impingement aperture permits fluid flow communication between the compressor and the cavity. The inner wall has a second area corresponding to the first area and defines a plurality of effusion apertures therein, the effusion apertures permitting fluid flow communication between the cavity and the combustion zone, and each of the effusion aperture defines a cross-sectional area smaller than that of the impingement aperture. The effusion apertures are disposed in groups having a predetermined geometric arrangement relative to the impingement aperture and define a ratio of number of effusion apertures to the impingement aperture of between about 2:1 and about 4:1.

Abstract: A three-stage lean burn combustion chamber (28) comprises a primary combustion zone (36), a secondary combustion zone (40) and a tertiary combustion zone (44). Each of the combustion zones (36, 40, 44) is supplied with premixed fuel and air by respective fuel and air mixing ducts (54, 70, 92). The fuel and air mixing ducts (54, 70, 92) have a plurality of air injection slots (62, 64, 76, 98) spaced apart transversely to the direction of flow through the fuel and air mixing ducts (54, 70, 92). The air injection slots (62, 64, 76, 98) extend in the direction of flow through the fuel and air mixing ducts (54, 70, 92) to the reduce the magnitude of the fluctuations in the fuel to air ratio of the fuel and air mixture supplied into the at least one combustion zone (36, 40, 44). This reduces the generation of harmful vibrations in the combustion chamber (28).

Abstract: In a gas turbine control apparatus, a frequency analyzing section frequency-analyzes at least one of pressure oscillation in combustors of a gas turbine and acceleration oscillation of each of the combustors and outputs a first frequency analysis result as the result of frequency analysis for a plurality of predetermined frequency bands. A control unit controls at least one of a first fuel flow rate of fuel and a first air flow rate of air based on the first frequency analysis result for the plurality of frequency bands. The fuel and the air are supplied to the gas turbine.

Abstract: A gas turbine combustor (10) having a first grouping (64) of pre-mix burners (12, 12?, 12?) having mixing passages (36) that are geometrically different than the mixing passages (38) of a second grouping (66) of pre-mix burners (14, 14?, 14?). The aerodynamic differences created by these geometric differences provide a degree of control over combustion properties of the respective flames (44, 46) produced in a downstream combustion chamber (40) when the two groupings of burners are fueled by separate fuel stages (52, 54). The geometric difference between the fuel passages of the two groupings may be outlet diameter, slope of convergence of the passage diameter, or outlet contour. The fuel injection regions (16, 18) of all of the burners may be identical to reduce cost and inventory complexity. The burners may be arranged in a ring (60) with a center pre-mix burner (68) being identical to burners of either of the groupings.

Abstract: A combustion liner cap assembly includes a cylindrical outer sleeve supporting internal structure therein and a plurality of fuel nozzle openings formed through the internal structure. A first set of circumferentially spaced cooling holes is formed through the cylindrical outer sleeve, and a second set of circumferentially spaced cooling holes is formed through the cylindrical outer sleeve. The second set of cooling holes is axially spaced from the first set of cooling holes. The resulting construction serves to decrease combustion dynamics in a simplified manner that is retrofittable to current designs and reversible without impacting the original configuration. The reduction in combustion dynamics improves hardware life, which leads to reduced repair and replacement costs.

Abstract: The objective is to provide a gas turbine and the combustor thereof in which super high frequency combustion oscillation and the generation of NOx are reduced. The fluctuation in pressure which induces the fluctuation in heat liberation is suppressed in the gas turbine combustor comprising a plurality of main fuel supply nozzles, each having a premixing nozzle at the top end part thereof, by providing in the space upstream from the premixing nozzles partition elements for dividing the space along the axis of the combustor or a honeycomb element having air passages in the axial direction, or by providing premixing nozzles composed of cylindrical elements with many holes.

Abstract: A gas turbine combustor in which a part or all of the wall of the combustor disposed within an intake chamber is formed as an acoustic energy absorbing member that can absorb the acoustic energy of a combustion variation generated within the combustor. The acoustic energy absorbing member is constructed of a thin corrugated plate in a circumferential direction, a high-temperature-proof perforated material, or a back plate disposed at the outside of a perforated plate in a radial direction with a distance from the perforated plate. It is also possible to provide a covering member at the outside of the acoustic energy absorbing member in a radial direction, for covering the acoustic energy absorbing member with a distance from the acoustic energy absorbing member. It is preferable that the acoustic energy-absorbing member and/or the covering member are reinforced with a frame that extends in a circumferential direction and/or a longitudinal direction.