来流速度突变对斜爆轰反射波系驻定特性影响的数值研究

The oblique detonation engine (ODE) is expected to be used in future hypersonic power systems, bringing many technical advantages to the engine by regulating the combustion mode. However, few studies concern the wave structure of an oblique detonation wave (ODW) in confined spaces, particularly for the stability of reflected wave systems under complex inflow conditions. On the basis of a simplified ODE combustor model, the effects of a changing inflow velocity on the steadiness of the oblique detonation reflected wave system are studied in this paper. The numerical results show that the evolution of the reflected wave system undergoes two processes, including long-term accumulation and sudden acceleration, which is unfavorable for an ODE application and can be efficaciously harnessed by increasing the inflow Mach number. The inflow disturbance aroused by this increase may restabilize the originally unstable reflected wave system, and the effects depend on the time and amplitude of the increase of the inflow Mach number. The earlier the disturbance occurs and the greater the increase in Mach number, the more easily a stable reflected wave system will develop. Furthermore, by analyzing the flow field characteristics of ODWs disturbed by inflow, the re-stabilization mechanism of a reflected wave system is revealed; that is, the flow choking induced by the subsonic zone behind the Mach stem is suppressed by the inflow disturbance.