Experimental investigation on combustion state in a dual-strut supersonic combustor

Staged injection in dual-strut supersonic combustor fueled by liquid kerosene was experimentally tested in directly-connected facility. Two kinds of steady combustion state were found in the identical incoming airflow condition and injection condition. If the fuel injected from upstream strut combusted locally then it was named as upstream-combustion state, and if the fuel injected from upstream strut combusted downstream then it was named as downstream-combustion state. This phenomenon was investigated from equivalence ratio distribution. In the condition of the total equivalence ratio being 1.0, a feature point was chosen by analyzing the results. The relationship between the pressure of the feature point and the equivalence ratio of the upstream was obtained through the dynamic injection experiments, and the conditions in which the two combustion states happened were described through this relationship. The results of one-dimensional impulse analysis method show that the thrust in upstream-combustion state was 73N higher than that in downstream-combustion state.