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

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 bench-marked 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 H-2/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 stream-wise 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.

Automated summary

The study investigates the mixing and combustion processes of the transverse injector and hypermixer in a Hyshot combustor under different equivalence ratios, revealing significant impacts of interactions between the stream-wise vortex and hypermixer on mixing and combustion efficiencies. As the equivalence ratio increases, the combustor with the hypermixer maintains higher combustion efficiency compared to the one with the transverse injector, which has already switched to the ramjet mode at high equivalent ratios.