不同结构形式凹面腔内的激波会聚起爆爆震波数值研究

Numerical Simulation of Detonation Initiation at the Convergence of Shock Waves Induced by Annular Centripetal Jets in Different Types of Concave Reflectors

为了研究利用环形径向向心射流产生的激波在凹面腔内会聚直接起爆可燃混合气过程,运用数值方法和基元反应机理,对抛物型、半球型、圆锥型3种形式的凹面腔中射流产生的激波会聚直接起爆H2/O2/N2混合气过程进行了数值对比研究。在抛物型、圆锥型凹面腔内成功利用激波会聚直接起爆爆震波,发现凹腔截面面积变化率越大越易于激波会聚起爆爆震波,抛物型凹腔与圆锥型凹腔相比底部过渡更为平滑,爆震起爆后不易出现压力奇点,与半球型凹腔相比截面面积变化率更大,是理想的激波会聚型面。

The detonating process of H2/O2/N2 mixture,which was directly initiated due to the convergence of shock waves induced by annular centripetal jets in parabolic,hemispherical and conical reflectors,was numerically contrastively investigated with the help of kinetic mechanism of hydrogen combustion to get insight into the phenomenon.And direct detonation ignition was established in parabolic reflector and conical reflector with the help of the convergence of shock waves induced by annular centripetal jets.It was found that a large section change rate of the concave reflector helps to converge the shock wave for explosion.The parabolic reflector has larger section change than the hemispherical reflector and smoother zenith zone than the conical reflector to keep away from singular point of extreme pressure after detonation.