来流状态对超声速气动斜劈诱导爆震起爆过程的影响

Influence of flow state on initiation process of oblique detonation wave induced by hydrodynamic wedge in supersonic combustible flow

超声速斜爆震热射流起爆特性受到气流状态参数的影响。针对低速持续热射流,采用高速激光纹影技术和压力传感器测压技术,研究低速热射流预混气来流当量比、温度和速度等状态参数的影响。实验发现,当量比对起爆过程的影响具有一定的随机性,但一般情况下,当量比的增加,有利于爆燃向爆震转变(Deflagration toDetonation,DDT)过程;提高来流温度,将缩短DDT时间,有利于起爆;而提高来流速度,则将阻碍剪切层发展,导致混合效果变差,不利于起爆。

The initiation characteristics of supersonic-speed oblique detonation thermojet are influenced by the airflow status parameters. The high speed laser schlieren technology and pressure sensor technology are adopted to study the influence of state parameters such as the thermojet premixed combustible gas equivalence ratio, inlet flow temperature and velocity on the low-speed continuous thermojet. It is found in the experiment that the influence of equivalence ratio on the initiation process has a certain randomness, but under general condition, increase of the fuel equivalence ratio will benefit DDT （deflagration to detonation）, increase of the inlet flow temperature will reduce the DDT time and benefit the initiation, and increase of the inlet flow velocity will result in poor mixing effect and will not benefit the initiation.