Turbine engine combustor having a tunable acoustic damper
A combustor for a turbine engine includes a wall defining a combustion chamber, and an acoustic damper. The acoustic damper includes a housing in fluid communication with the combustion chamber through an opening provided in the wall, the housing defining a cavity and having one or more neck holes in fluid communication with the combustion chamber, and a mechanism configured to vary a damping acoustic frequency of the acoustic damper so as to vary the damping acoustic frequency of the acoustic damper to align with an acoustic frequency of acoustic vibrations generated in the combustion chamber to attenuate an acoustic instability within the combustion chamber.
1 . A combustor for a turbine engine, the combustor comprising:
a wall defining a combustion chamber; and
an acoustic damper comprising:
a housing in fluid communication with the combustion chamber through an opening provided in the wall of the combustion chamber, the housing mounted to the combustor via an armature, the housing defining a cavity and having a lateral wall, one or more neck holes in fluid communication with the combustion chamber, and one or more purge holes provided within the lateral wall of the housing, the one or more neck holes being provided on a face plate of the housing facing the combustion chamber; and
a mechanism configured to vary a damping acoustic frequency of the acoustic damper via a piston moving through the armature to align with an acoustic frequency of acoustic vibrations generated in the combustion chamber to attenuate an acoustic instability within the combustion chamber and the one or more purge holes are provided between the armature and the face plate.
2 . The combustor of claim 1 , further comprising a sensor and an actuator, the sensor configured to measure the acoustic frequency of the acoustic vibrations generated in the combustion chamber and to send a measurement signal to a controller in communication with the sensor, the controller configured to send a control signal, based on the measurement signal, to the actuator in communication with the controller to control the mechanism to vary the damping acoustic frequency of the acoustic damper.
3 . The combustor of claim 1 , wherein the piston is configured to move within the cavity of the housing to vary a length of the cavity so as to vary the damping acoustic frequency of the acoustic damper.
4 . A turbine engine comprising:
a compressor section, a combustion section downstream of the compressor section, and a turbine section downstream of the combustion section, the combustion section having a combustor comprising:
a wall defining a combustion chamber; and
an acoustic damper comprising:
a housing in fluid communication with the combustion chamber through an opening provided in the wall of the combustion chamber, the housing mounted to the combustor via an armature, the housing defining a cavity and having a lateral wall, one or more neck holes in fluid communication with the combustion chamber, and one or more purge holes provided within the lateral wall of the housing, the one or more neck holes being provided on a face plate of the housing facing the combustion chamber; and
a mechanism configured to vary a damping acoustic frequency of the acoustic damper via a piston moving through the armature to align with an acoustic frequency of acoustic vibrations generated in the combustion chamber to attenuate an acoustic instability within the combustion chamber and the one or more purge holes are provided between the armature and the face plate.
5 . The turbine engine of claim 4 , wherein the combustor further comprises a sensor and an actuator, the sensor configured to measure the acoustic frequency of the acoustic vibrations generated in the combustion chamber and to send a measurement signal to a controller in communication with the sensor, the controller configured to send a control signal, based on the measurement signal, to the actuator in communication with the controller to control the mechanism to vary the damping acoustic frequency of the acoustic damper.
6 . The turbine engine of claim 4 , wherein the piston is configured to move within the cavity of the housing to vary a length of the cavity so as to vary the damping acoustic frequency of the acoustic damper or a bellows configured to move within the cavity of the housing to vary the length of the cavity so as to vary the damping acoustic frequency of the acoustic damper.