On the Accoustics of Rocket Combustors Euqipped with Quarter Wave Absorbers

Kurzfassung

The acoustic resonance spectrum and the dissipation of specific modes in combustors equipped with absorbers have been investigated experimentally and numerically. It is found that the application of absorber rings to a combustor is changing its resonance behavior significantly. Based on the acoustic fields obtained by 3D-modal analysis the damping behavior for modes is predicted and compared to measurements. There is good agreement between prediction and experimental data with respect to the general trend of the dependence of damping on the absorber length. However the experimentally determined disspation rates are significantly larger than the predicted values.