Study on integrated aeroramp injector/gas-pilot flame in a supersonic combustor

Experimental and numerical study of a novel integrated flush-wall aeroramp injector/gas-pilot flame has been conducted in a scramjet combustor. The aeroramp injector consisted of four flush-wall holes. Downstream of it, the gas-pilot flame as located as igniter and flame holder. The experiment's facilities can deliver a continuous supersonic flow of Mach number 2.0 with a total temperature of 1200 K. In the cold flow tests, schlieren and surface oil-flow visualization pictures in the vicinity of injectors were taken to obtain a qualitative assessment of the injectors flowfields. The detailed characteristics of cold flowfields were numerically simulated, which agreed well with the experimental results. Some important parameters, such as mixing efficiency, penetration depth, and maximum concentration decay, were investigated to analyze the mixing performance. In the hot flow tests, ethylene was injected into the mainstream at jet-to-freestream momentum flux ratios q between 1.2 and 3.9. One-dimensional performance analysis of the test data indicates combustion efficiencies as high as 90% in all cases. This was the first time that the integration of an aeroramp injector/gas-pilot flame for supersonic combustion was studied. The results show that this novel injection and flame holding configuration for supersonic combustion is feasible.