Experimental Research on Ignition Process of a Supersonic Combustor Based on a Strut Fueled with Liquid Kerosene

Abstract

The ignition process in a thin strut equipped supersonic combustor fueled with liquid kerosene was observed to deepen the understanding of the ignition characteristics. A large number of experiments were carried out under the conditions of Tt=1,680 K, Pt=1.87 MPa, and Ma=2.8. The combustion establishment process and the flame characteristics were captured and reproduced by a high speed camera. Results show that the flame is first established near the igniter flame in the lower half of the combustor under the action of the recirculation zone and oxygen supplement at the end of the strut. Then, the flame spreads to the main flow of the combustor. The ignition process under different equivalence ratios was compared and studied. The results indicate that the ignition delay time and the flame distribution of the ignition process are affected by the equivalence ratio. At the same time, it was found that there are two modes in the flame establishment process, namely, the upstream propagation mode and the downstream propagation mode. The flame propagation speeds in different directions under these two propagation modes are different. The results presented in this paper are valuable for the future optimization of ignition performance in a scramjet combustor using kerosene fuel injection.