Mixing and transient combustion processes of scramjet combustor with transverse injector and hypermixer

Abstract

The supersonic mixing between the reactive injection with an airstream is an essential issue that determines the scramjet engine performance. The mixing and transient combustion processes under different equivalence ratios for both the transverse injector and hypermixer in a benchmarked Hyshot combustor are numerically investigated with a Mach 2.49 inlet flow. The improved delayed detached eddy simulation (IDDES) coupled with the Thickened Flame Model and seven species and seven reactions for the H2/air reaction mechanism was used to investigate differences in the mixing, shock structure, combustion mode, and combustion efficiency between the transverse injector and hypermixer. The results show that interactions between the streamwise vortex and hypermixer significantly impact the mixing and combustion enhancements. The combustors with the hypermixer and transverse injector are both in the scramjet mode at the equivalence ratio of 0.295. As the equivalence ratio increases to 0.593, the combustor with the hypermixer is still in the scramjet mode, but the combustor with transverse injector is already in the ramjet mode. The numerical results show that compared with the general transverse injector scheme, the scramjet combustor with the hypermixer has higher mixing and combustion efficiencies.