气相爆轰波马赫反射过驱动马赫杆演化过程的实验研究

The transition of an overdriven Mach stem in the Mach reflection of cellular detonations on the wedge is experimentally studied in mixtures of hydrogen and oxygen with different argon dilutions. This study focuses on the changes in the cell size of an overdriven Mach stem on the wedge surface other than those on the sidewall. The detonation cell pattern on the wedge surface has a complicated process, i.e., the cells decrease from a large to a small size and then increase asymptotically to a medium size, which can be considered a three-stage pattern. The changes in cell size in this case do not correspond to the normal cell-size change in a decaying overdriven detonation. This is primarily attributed to the mixed effect of Mach reflection and cellular instability. Furthermore, the cell-size ratio upon increasing the degree of overdrive is examined. It is found that the ratio decreases with increase in the degree of overdrive. However, as the wedge angle increases to a critical value, finer cells are not created on the smoke foils.