Mach reflection in steady supersonic flow with two incident shock waves that reflect at the same point on the reflecting surface has been studied recently. Under some conditions we have pre-Mach reflection, where the first incident shock wave produces Mach reflection, the reflected shock wave of which intersects the second incident shock wave, leading to a type I shock interference structure. In this study, we find that a critical condition exists to have a double solution of this shock interference, i.e. we may either have type I interference or type II interference. However, numerical simulation shows that, for inverted Mach reflection, the double solution domain is below the theoretical one and for usual Mach reflection, the double solution domain is above the theoretical one. This discrepancy is found to be due to secondary Mach waves on the initial segment of the slipline of the Mach reflection, thus demonstrating for the first time a case where the transition criterion is modified by secondary Mach waves developed over the primary flow structure.

中文翻译：

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二次波对两入射激波前马赫反射激波干涉跃迁判据的双重解及影响

最近研究了在具有两个入射冲击波的稳定超音速流中的马赫反射，这些冲击波在反射面上的同一点反射。在某些情况下，我们有前马赫反射，其中第一个入射激波产生马赫反射，其反射激波与第二个入射激波相交，导致 I 型激波干涉结构。在这项研究中，我们发现存在一个临界条件来解决这种冲击干扰的双重解，即我们可能有 I 型干扰或 II 型干扰。然而，数值模拟表明，对于倒置马赫反射，双解域低于理论值，而对于普通马赫反射，双解域高于理论值。