Flow and combustion process for wide speed range scramjet: Review

The increasing demand for future hypersonic vehicle maneuvers heightens the importance of the wide speed range scramjet technology development. However, the wide-range inflow conditions will cause significant changes in the flow, mixing, and combustion processes. In particular, supersonic combustion is a typical diffusion flame dominated by the mixing process, and changes in the inflow conditions have a considerable impact on the fuel transport and mixing process, which can lead to a series of unsteady combustion phenomena. This paper reviews and analyzes the flow and combustion process of the wide speed range scramjet. Firstly, the basic working process and applications of scramjets are briefly introduced. Then the key problems in and research on the supersonic flow and combustion process with the low Mach number inflow, high Mach number inflow and wide speed range inflow at home and abroad are discussed, followed finally by a summary and suggestions for follow-up research.