爆轰波-激波迎面作用后的稳定波系

本文为对当量比乙炔氧气混合气体中爆轰波与激波正面对撞产生稳定波系的实验和理论研究.实验主要以高速扫描摄影获取两波对撞的x-t纹影图,一维理论分析则基于三种热完全的组分求解两波对撞的稳定解并探寻它们的规律.实验发现透射波系包括一道激波和爆轰波,以及紧随爆轰波后的稀疏波区,这种波系情况与一维理论分析中CJ解一致.透射CJ爆轰与人射爆轰相比马赫数降低,而相对波前来流的传播速度有轻微提高,但在实验室坐标下其速度显著降低.透射波系受初始压强影响不大;初始温度提高使得爆轰波速度降低,而透射激波速度增加;对波系起实质影响作用的是入射激波强度,激波越强,则整个透射流场呈现偏向激波的趋势;理论分析还指出,稀疏波区的出现不可避免,当激波强度趋于声波时稀疏波区趋于消失,激波越强则疏波区趋于扩大.

The steady wave system after head- on collision of detonation and shock wave

An experimental and theoretical study on the steady wave system after head - on collision of a detonation wave with shock wave was carried out. Experimentally, high speed streak sehlieren photography was used to illustrate the interacting flow field. And theoretically, 1 - dimensional analytic works based on 3 combined species were also performed to find the steady solution of the collision problem and its essential characteristics. The x - t streak schlieren photos demonstrate that the steady wave system after collision consists of a shock wave and a detonation wave followed by a rarefaction wave fan, and this result is consistent with the CJ solution of 1 - D theoretical analysis. By the impact of incident shock, the Mach number of transmitted detonation decreases, while the propagation speed of it relative to the flow ahead is slightly increased and in laboratory frame it shows up to be decreased due to the shockinduced opposite flow. The wave system is barely depending on the initial pressure of the mixture, while initial temperature can remarkably decrease detonation speeds and increase transmitted shock speed. The strength of the incident shock wave serves as the most important parameter that controls the transmitted flow system. Stronger shock pulls the whole flow field towards the shock direction more seriously. Rarefaction is inevitable in the system unless the incident shock tends to Mach one, and stronger shock usually results in more expanded rarefaction zone.