关键词: 气相爆轰；马赫反射；爆轰不稳定性；胞格结构；活化能

Abstract: In order to study the Mach reflection of oblique detonation wave and the influence of instability on Mach reflection，three premixed mixture with different quantitative instability were investigated in a rectangular channel. The smoked foils were used to obtain the experimental results. The results clarified that the height of triple point was similar with the non-reactive three shock theory near the apex，but in far field，it turned to deflect to the reactive three shock theory. In fact，practical reactive heat determines the height of Mach stem，while it is related to the activate energy of three premixed mixture that the ratio of the distance between the triple point trajectory begins and ends deflection to the distance where the triple point ends deflection is 0.42，0.49，0.31，respectively. With the initial pressure increasing，the cellular structure became more regular and the size became smaller. Also，the cellular structure transited apparently from CJ zone to overdriven zone. Transverse wave can be considered as a main influence factors on oblique detonation. Increasing pressure can reduce the molecule random movements so that the position where the transverse wave forms became more concentrated. It lead to the cellular structure becoming more regular as well. What’s more，higher instability of premixed mixtures result in more difficulty of determination of the transverse wave forming position in space and time，higher irregularity of cellular structure and smaller cell size.

Key words: Gaseous detonation；Mach reflection；Detonation instability；Cellular structure；Activate energy