采用不同化学反应源项处理方法的胞格爆轰数值研究

Numerical Simulation of Cellular Detonation Using Different Chemical Reacting Source Term Methods

采用一种改进的化学非平衡流解耦方法对Euler反应流方程进行解耦处理,对流项采用五阶WENO格式进行离散,化学反应源项分别采用梯形公式和α-QSS拟稳态逼近两种方法处理,时间步进采用二阶精度的Runge-Kutta方法,对H2/O2/Ar预混气的胞格爆轰进行了二维数值模拟。两种处理方法都得到了合理的三波点结构,计算结果接近,但α-QSS拟稳态逼近处理方法的化学反应较完全,爆轰波传播速度较高;揭示了爆轰波结构的发展变化过程,横波与横波、横波与壁面碰撞引起的二次起爆对爆轰波的稳定发展至关重要;分析了数值胞格结构,胞格长宽比与参考文献基本一致,验证了本计算方法的有效性。

An improved de-coupled solver of non-equilibrium flow was used to split the Euler equations for a reacting flow.Inviscid flux was calculated with fifth-order WENO scheme.Trapezoid formula and α-QSS methods were applied to deal with the stiffness generated by the chemical reacting source term of species equations separately.Time integration was performed with two-order TVD Runge-Kutta scheme.Cellular detonation of H2/O2/Ar in a straight tube was numerically studied.Calculated results by different methods were similar,and triple point structures were analyzed.The releasing heat of chemical reaction dealt with by α-QSS method is higher than that by trapezoid formula,so the detonation wave propagating speed of α-QSS method is higher than that of trapezoid formula too.Development of cellular structure was elaborated.Due to interactions between transverse waves and between transverse wave and tube wall,re-initiation was ignited,which plays a crucial role in the propagating of detonation wave.Ratio of numerical cellular structure length to width is consistent with reference value,which indicates the feasibility of the numerical method.