Damping system for high frequency combustion instabilities in a combustion chamber

摘要

The damping system comprises at least one resonant acoustic cavity disposed around the combustion chamber and having a shape and dimensions such that it functions simultaneously as a quarter-wave resonator and with tangential coupling the resonant acoustic cavity comprises: a) a main annular part whose half axial section has a very elongate shape with a width dimension "e" which is very small compared to its longitudinal dimension "L1" which extends substantially parallel to the axis of symmetry of the combustion chamber, the mean radius "R" of the main annular part being close to the equivalent radius of modes of oscillation to be damped, and b) an annular coupling part which originates from the main annular part and which opens into the combustion chamber near to a longitudinal or radial pressure anti-node, the annular coupling part having a length "L2" in a half axial section and a width dimension "h" very much less than the sum of the longitudinal dimension "L1" of the main annular part and the length "L2" of the annular coupling part.