对高温火团引发的甲烷-空气混合气体的爆轰过程及管内、外流场做了二维轴对称数值模拟,考虑了CH4-O2-N2的详细化学反应动力学机理,该机理包含了19个基元反应和14种组分。采用分裂格式处理带化学反应的Navier-Stokes方程,使用改进的波传播方法求解流场,使用基于隐式Gear算法的微分方程解法器求解化学反应过程。模拟结果显示了爆轰波在管内的成长、稳定传播、进入喷嘴后衰减为激波以及进入外流场的全过程。还对轴线上的压力分布和封闭端的推力等进行了讨论,为脉冲爆轰发动机的开发研制提供信息。
By solving two-dimensional axisymmetric Navier-Stokes equations in conjunction with the chemistry, a numerical simulation of pulse detonation process induced by flame in the tube with CH4 -O2 -N2 mixture and the flow field outside is performed, and a detailed chemical mechanism of CH4 -O2 -N2 system of 19 element reactions and 14 species is involved. A splitting operator method is used to treat the hydrodynamical process and the chemical process in the detonation simulation. The improved wave propagation algorithm is used to capture the shock wave and a gear algorithm is used to solve the chemical reaction, The computational results demonstrate the process of the development, steady propagation, degeneration into a shock after the detonation wave' s going into the nozzle and going into the external flow field, The pressure distribution of axis and the headend (thrust wall ) thrust history are disscussed, The results provide references for developing the pulse detonation engine.