Patent Application
20130283799
The present disclosure relates to a resonance damper for damping acoustic oscillations, and more particularly to a resonance damper for damping acoustic oscillations within a combustor housing of a gas turbine engine.
A resonance damper is provided in a gas turbine engine to damp acoustic oscillations produced by components within the engine thus avoiding detrimental effects to the service and life of the gas turbine engine. U.S. Pat. No. 7,076,956 relates to a combustion chamber suitable for a gas turbine engine. The combustion chamber 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.
In one aspect, the present disclosure provides a resonance damper for damping acoustic oscillations within a combustor housing of a gas turbine engine. The resonance damper includes a container, an opening, and a pipe. The container is configured to be attached to an interior wall of the combustor housing and has a cavity. The opening is provided on the container. The pipe is rigidly connected to the opening to define the resonance damper with the cavity.
In another aspect, the present disclosure provides a combustor housing of a gas turbine engine. The combustor housing includes a combustor and the resonance damper for damping the acoustic oscillations within the combustor housing. The combustor produces the acoustic oscillations. The resonance damper includes the container, the opening, and the pipe. The container is configured to be attached to the interior wall of the combustor housing and has the cavity. The opening is provided on the container. The pipe is rigidly connected to the opening to define the resonance damper with the cavity.
In another aspect, the present disclosure provides a gas turbine engine including a compressor system, multiple injectors, and the combustor housing. The injectors are adapted to receive compressed air from the compressor system. The injectors are further adapted to premix and supply fuel and air. The combustor housing includes the combustor and the resonance damper for damping the acoustic oscillations within the combustor housing. The combustor is operatively connected to the injectors. The combustor is configured to receive and combust the premixed fuel and air thereby producing acoustic oscillations. The resonance damper includes the container, the opening, and the pipe. The container is configured to be attached to the interior wall of the combustor housing and has the cavity. The opening is provided on the container. The pipe is rigidly connected to the opening to define the resonance damper with the cavity.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.
The present disclosure relates to a resonance damper for damping acoustic oscillations within a combustor housing of a gas turbine engine.
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Further, as shown in
The acoustic oscillations radiating from the combustor 110 reflect away from interior walls 114 of the combustor housing 104 thus moving successively to and fro within the combustor housing 104. There is a possibility that two or more acoustic oscillations may undergo constructive interference thus increasing the amplitude of the resulting acoustic oscillation, also known as, dynamic pressure oscillation.
Further, as shown in
In one embodiment, the resonance damper 112 is positioned in a predetermined region of maximum dynamic pressure fluctuations within the combustor housing 104. In this embodiment, the extent of length L of the combustor housing 104, at which the resonance damper 112 is positioned, may be decided based on predetermined calculations that show a region in the combustor housing 104 where the dynamic pressure fluctuations are substantially. Further, the position of the resonance damper 112 is selected based on a pre-determined mode shape of the acoustic oscillations or dynamic pressure fluctuations within the combustor housing 104. Furthermore, a number of such resonance dampers 112 may be provided within the combustor housing 104 depending on the amount of resonance damping required. The number of resonance dampers 112 may be selected such that the required amount of resonance damping is achieved by providing an optimal amount of acoustic connectivity between an interior 124 of the combustor housing 104 and the respective cavities 122.
Further, as shown in
In an embodiment as shown in
In the preceding embodiments, it is disclosed that the pipe 120 is rigidly connected to the opening 118 by welding and that the front plate 130 and the back plate 132 are rigidly connected to opposing ends 134, 136 of the hollow tube 128 by welding. However, a person having ordinary skill in the art will appreciate that the rigid connection of the pipe 120 to the opening 118, and the front and the back plate 130, 132 to the opposing ends 134, 136 of the hollow tube 128 by welding, is only exemplary in nature and that any other method known in the art may be used to accomplish these rigid connections.
In the embodiment as shown in
In an embodiment as shown in
In an exemplary embodiment as shown in
When the mixture of fuel and air is combusted in the combustor 110, energy is generated. A component of this energy may be released as acoustic energy which may manifest itself in the form of acoustic oscillations. As already known to a person having ordinary skill in the art, these acoustic oscillations are a type of mechanical wave that propagate with the help of a fluid medium present within the combustor 110 and the combustor housing 104. Generally, the fluid medium present within the combustor 110 is the mixture of fuel and air while the fluid medium present within the combustor housing 104 is air.
The acoustic oscillations radiating from the combustor 110 reflect away from the interior walls 114 of the combustor housing 104 thus moving successively to and fro within the combustor housing 104. There is a possibility that two or more acoustic oscillations may undergo constructive interference thus increasing the amplitude of the resulting acoustic oscillation, also known as, dynamic pressure oscillation.
As known to a person having ordinary skill in the art, many components in the combustor housing 104 have a natural frequency of vibration. When a frequency of acoustic oscillations or dynamic pressure oscillations matches the natural frequency of any component within the combustor housing 104, the specified component may undergo vibrations and subsequently fail. Further, if the frequency of acoustic oscillations or dynamic pressure oscillations matches the natural frequency of the combustor housing 104, the combustor housing 104 itself may fail. Hence, the combustor housing 104 and the components present therein need to be protected from prolonged exposure to the acoustic oscillations or the dynamic pressure oscillations. Further, fluctuations in the amplitude of the dynamic pressure oscillations can be large enough to cause failure of the combustor housing 104 and the components present therein. Furthermore, the fluctuations in the amplitude of the dynamic pressure oscillations may, at the very least, reduce the service life of the combustor housing 104 and the components present therein, even if the frequency of the acoustic oscillation is substantially different from the natural frequency of the combustor housing 104 and the components therein. Failure of the components or the combustor housing 104 may be detrimental to the safe operation of the gas turbine engine 100 and hence, damping of acoustic oscillations or dynamic pressure oscillations to safe and acceptable limits may be required.
Further, as known to a person having ordinary skill in the art, a fluid medium, for example, air, exists in the combustor housing 104. The resonance damper 112 may be analogous to a spring mass damper system, wherein the air in the throat 126 of the resonance damper 112 acts as a mass in the spring mass damper system while the air in the cavity 122 of the resonance damper 112 acts as a spring in the spring mass damper system. Frictional forces between the air in the throat 126 and the walls of the throat 126 act to dampen the dynamic pressure oscillations outside the resonance damper 112 while the air in the cavity 122 acts as a resilient spring to phase-shift and cause destructive interference among successive dynamic pressure oscillations. Hence, dynamic pressure oscillations are effectively damped by the resonance damper 112.
In an embodiment, multiple resonance dampers 112 may be annularly arranged within the combustor housing 104 of the gas turbine engine 100. The multiple resonance dampers 112 define multiple cavities 122 and may function analogous to multiple Helmholtz resonators arranged in an annular pattern to damp the dynamic pressure oscillations within the combustor housing 104.
In another embodiment, a single annular cavity 122 may be defined by an annular resonance damper 112. Further, the annular resonance damper 112 may include several pipes 120 and throats 126 therein leading to the single annular cavity 122. The tubes 120 and throats 126 may provide acoustic connectivity between the interior 124 of the combustor housing 104 and the annular cavity 122. The resonance damper 112 of this embodiment may be used to uniformly bleed air from within the combustor housing 104 for stability control of the gas turbine engine 100.
The use of the resonance damper 112 in the gas turbine engine 100 may allow smoother operation of the gas turbine engine 100. Further, the use of resonance dampers 112 in a gas turbine engine 100 may result in lower maintenance costs by avoiding frequent repairs and replacement of components within the gas turbine engine 100 otherwise impacted by large acoustic oscillations or dynamic pressure oscillations. Furthermore, down times required for repairs and replacement of components within the gas turbine engine 100 may be reduced. Hence, the resonance damper 112 may increase overall productivity and profitability associated with the gas turbine engine 100.
Furthermore, existing combustor housing structures defining internal spaces could be used to position the resonance damper 112 within the combustor housing 104. For example, in an existing combustor housing 104 defining an internal space, the resonance damper 112 may be positioned within the combustor housing 104 while the container 116 may be attached to the interior wall 114 of the combustor housing 104. The compact construction and configuration of parts of the resonance damper 112 make it retrofittable, since existing structures and spaces can be repurposed for acoustic damping purposes. Thus, the resonance damper 112 and subsequently the gas turbine engine 100 may be quickly set up with minimal effort and modifications saving time and expense.
While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machine, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.
