双点激光点火直接起爆的数值模拟

针对双点激光点火直接起爆过程中爆轰波的形成、发展和传播问题,采用高精度数值模拟方法求解带化学反应的二维欧拉方程组,研究了不同环境压力情况对流场结构与波系变化的影响.结果表明,环境压力会影响激波强度与爆轰波的传播速度,是决定双点激光点火形成的火核在碰撞过程中能否实现爆轰并维持爆轰波传播的重要因素,利用双激光点相互作用形成强反射激波,有助于实现可燃气的直接起爆;当环境压力在15~120 kPa之间时,火核的碰撞实现了直接起爆,流场中形成稳定传播的爆轰波;爆轰波锋面上横波的碰撞与三波点形成是维持爆轰传播的重要机制,随着环境压力的升高,爆轰波锋面三波点数量增多,横波的传播机制发生改变.

Numerical Simulation of the Direct Initiation by Double-Point Laser Ignition

Aimed at the formation,development and propagation of detonation wave in the process of direct initiation of double-point laser ignition,the high-precision numerical simulation method is used to solve the twodimensional Euler equations with chemical reaction,and the influence of different environmental pressures on the change of flow field structure and wave system is studied.The results show that the environmental pressure will affect the shock intensity and the detonation wave propagation speed,and it is an important factor in determining whether the double-point laser ignition kernel can realize detonation and maintain the detonation wave propagation in the collision process.When the environmental pressure is between 15—120 kPa,the direct initiation is realized by the collision of fire kernel and the detonation wave with steady propagation is formed in the flow field.The collision of transverse wave and the formation of triple points on the front of detonation wave are important mechanisms to maintain detonation propagation.With the increase of environmental pressure,the number of triple points on the front of detonation wave increases,and the propagation mechanism of transverse wave changes.