System for damping high frequency combustion instabilities in a combustion chamber.

摘要

The damping system comprises at least one resonant acoustic cavity (10, 20) arranged around the combustion chamber (2) and having a geometry and dimension such that it operates simultaneously as a quarter wave resonator and as a tangential coupling. The resonant acoustic cavity (10, 20) comprises: a) an annular main part (20) of which the cross-section through an axial half-plane has a very elongate shape with a transverse dimension "e" which is very small with respect to the longitudinal dimension "L1" which itself extends substantially parallel to the axis of symmetry of the combustion chamber, the mean radius "R" of the annular main part (20) being close to the equivalent radius of the vibration modes to be damped, and b) an annular communication part (10) which starts off in the annular main part (20) and opens out into the combustion chamber (20) close to a longitudinal or radial pressure antinode, the annular communication part (10) having, in cross-section through an axial half-plane a length "L2" and a transverse direction "h" which is very much less than the sum of the longitudinal dimension "L1" of the annular main part (20) and of the length "L2" of the annular communication part (10). <IMAGE>