Combustion stability of a homogeneous mixture in a chamber lined with acoustic absorbers

Self-excited oscillations in cylindrical combustion chambers burning a homogeneous mixture are investigated theoretically and experimentally. It is shown that two low-order tangential-longitudinal modes differing slightly in frequency are excited in the model chamber. Judging from the closeness of the experimental and theoretical values obtained for the mass flow rate of the mixture at the self-excitation boundary, it is postulated that excitation is due to the dependence of chemical reaction rate on the pressure (temperature) of the medium.