Effect of scramjet combustor configuration on the distribution of transverse injection kerosene

The effect of combustor configuration on the distribution of transverse injection kerosene was investigated in a direct-connected supersonic combustor equipped with multi-cavities, at the inflow condition of Ma = 2.64. The combustor configuration included a single cavity, cavities in tandem and cavities in parallel. The distribution of kerosene injected upstream of a cavity was observed by high speed photography. The experiments showed that the kerosene transverse jet shows strong turbulence characteristics. Only a small portion of kerosene can be engulfed into the cavity, as the main portion is transported downstream in the core flow. Even with a high injection pressure, the kerosene jet from one side of the combustor cannot achieve a well distribution, since the kerosene cannot cross through the main flow to reach the opposite side wall. Double cavities in tandem show a better performance in improving mixing and penetration for kerosene in the core flow, and the sequence of cavities seems have no effect on the injection. By increasing the fuel injection pressure, more kerosene is injected into the core flow, and less is engulfed into the cavity.