Combustion instabilities were studied experimentally by coupling unsteady heat release and pressure perturbations.In this paper

the experimental studies were conducted to analyze the dynamic processes of self-excited combustion oscillations through dynamic pressure and phase-locked chemiluminescence measurements.The effects of air mass flow

equivalence ratio and boundary conditions on combustion system were examined.This shows that the amplitudes of oscillation will enlarge with the increasing system load

leading to more unstable combustion.Moreover

the higher modes of oscillation frequency may occur when the combustion operation is closer to lean limits.