Patent ID: 7331182

Claim:
A combustion chamber for a gas turbine, the combustion chamber being surrounded by a gas turbine casing inside of which is disposed a plenum filled with compressed air, the plenum surrounding the combustion chamber, and the combustion chamber being separated from the plenum by a combustion chamber casing, the combustion chamber comprising at least one Helmholtz damper for damping thermoacoustic oscillations, the Helmholtz damper having a damping volume in communication with the combustion chamber via a connecting passage, wherein the Helmholtz damper is configured to have a damping frequency that is adjustable, the damping volume being divided into a fixed damping volume arranged inside the combustion chamber casing and being in fluid communication with the combustion chamber, and a variable damping volume arranged within the plenum and being in fluid communication with the combustion chamber, the damping volume being varied by changing the variable damping volume, and the fixed damping volume being selectable so that the damping frequency is proximate a frequency of a thermoacoustic oscillation of the combustion chamber and adjustable by changing the variable damping volume.