激波聚焦诱导点火和爆轰的数值研究

以二维轴对称多组分Euler方程为基础，采用非正交结构化网格和改进的波传播算法，模拟了激波在抛物形反射壁面聚焦反射诱导点火和爆轰的过程，描述了其流场形态。讨论了预混气组成、入射激波强度及反射壁面形状对点火和爆轰的影响。结果表明，激波在抛物形反射壁面顶点处聚焦反射可形成局部高温高压区域，该区域在一定条件下可点燃预混气甚至形成爆轰，其中低稀释剂浓度的预混气、较大的入射激波Mach数和较深的反射壁面有利于可燃预混气形成爆轰。

Numerical Studies on initiation and detonation induced by shock wave focusing

Based on the two-dimensional axisymmetric Euler equations, the initiation and detonation process of CH4/O2/N2 premixed gas induced by reflected focusing shock wave over the parabolic reflector was investigated numerically, using the nonorthogonal structured meshes and an improved reactive wave propagation algorithm. The flow field structures of detonation process were described. The effects of different compositions of premixed gas, incident shock wave intensities and reflector shapes on initiation and detonation were discussed. The results showed that the reflected focusing shock wave produced a local high temperature and high pressure region in the vicinity of the reflector apex, the region could ignite the premixed gas and lead to the detonation. The low diluted concentration of premixed gas, the high incident shock wave Mach number and the deeper reflector were of benefit to form detonation.