Experimental study of flame stabilization in a kerosene fueled scramjet combustor

Abstract

Kerosene flame stabilization in a Mach 2.0 model combustor was studied experimentally by using laser-induced fluorescence and high-speed photography. The interferential fluorescence in OH-PLIF was eliminated by the comparison with kerosene-PLIF. The reaction layers of flame were marked by the sharp gradient regions of fluorescence intensity in OH-PLIF. The results show that the flame is stabilized in the cavity at a lower equivalence ratio. As the equivalence ratio is increased, flame is stabilized in the cavity shear layer and spreads into the mainstream. The oscillations of the flame are quantified and correlated with the pressure fluctuations of the pseudoshock. Low-frequency oscillations are found to be amplified in the upstream propagation. As the inlet stagnation temperature rises, ram-scram transition occurs at a higher equivalence ratio. Kerosene flame is always stabilized in the cavity region without propagating upstream within the range of current inlet stagnation temperature (885–1285 K).