激波反射诱导二次起爆的数值分析

Numerical analysis of re-initiation phenomenon induced by shock reflection

以分叉管为例,研究了激波反射诱导气相爆轰二次起爆的现象.采用二阶附加半隐的龙格-库塔法和5阶WENO格式求解二维欧拉方程,并用基元反应来描述爆轰化学反应过程.结果表明:与化学反应区分离的诱导激波在垂直支管右壁面反射;反射激波在诱导激波压缩后未燃气体中传播,使得波后压力和温度进一步升高,诱导热点产生和局部爆炸,导致二次起爆.在水平和垂直支管中,诱导激波出现由规则反射向马赫反射转变.计算得到的二次起爆过程波系演变与实验纹影照片基本一致.

The re-initiation phenomenon of gaseous detonation induced by shock reflection in a bifurcated tube was studied. The 2^nd additive semi-implicit Runge-Kutta method and 5^th order WENO scheme were used to solve two-di- mensional reactive Euler equations. Detailed chemical reaction model was utilized to describe the heat release of detonation. The results show that, the decoupled leading shock reflects on the right wall of the vertical branch. High temperature and pressure behind the reflected shock induce the generation of hot spots and local explosion. Then, the re-initiation of gaseous detonation occurs. The transition of leading shock from regular reflection to Mach reflection respectively happens in the horizontal and vertical branches. The computed evolution of detonation wave involving the re-initiation is in good agreement with the schlieren images.