Effects of Mach Number on Non-Rankine–Hugoniot Shock Zone of Mach Reflection

Using the direct simulation Monte Carlo method, the non-Rankine–Hugoniot shock zone of steady Mach reflections with different inflow Mach numbers (five to eight) in hypersonic flows was numerically investigated. The differences in the global curvatures of the Mach stems were compared. The reduced global curvature of a Mach stem was obtained with an increased inflow Mach number when the influence of the height of the Mach stem was eliminated. The size of the non-Rankine–Hugoniot shock zone was independent of the inflow Mach number because of an approximately identical shock thickness in the considered cases. Furthermore, the feature of the pressure hot spot near the three-shock intersection was investigated comprehensively. An increase in Mach number resulted in an enhanced pressure hot spot. The boundary layers developing on both sides of the slipstream were integrated to explain and predict the formation and magnitude of the pressure hot spots, and good agreement was observed between the predicted results and the numerically simulated ones.