旋转爆轰自持机理的数值研究

Numerical Investigation on Self-sustaining Mechanism of Rotating Detonation

为研究旋转爆轰的自持机理,基于带化学反应的二维Euler方程,对2H2/O2/Ar系统在圆环管内爆轰的传播进行了数值模拟.用二阶附加半隐的Runge-Kutta法和五阶WENO格式分别离散欧拉方程的时间和空间导数项,采用基元反应简化模型描述爆轰化学反应过程,得到了旋转爆轰流场温度、压力、典型组元OH质量分数的分布及数值胞格结构.结果表明,爆轰波在圆环管中传播时,受壁面敛散性的影响,沿圆环凹壁面一侧流场的温度、压力和化学反应强度均高于凸壁面侧,而胞格尺寸则要小于凸壁面侧;旋转爆轰波沿凹壁面的传播速度要大于沿凸壁面的速度.数值计算得到的胞格结构与实验结果定性一致.

To study the self-sustaining mechanism of rotating detonation,based on two-dimensional Euler equations associated with chemical reactions,gaseous detonation of 2H2/O2/Ar mixture propagation through an annular tube was investigated numerically.Second-order additive semi-implicit Runge-Kutta method and the fifth-order weighted essentially non-oscillatory（WENO）scheme were used to discretize the time term and the spatial derivatives,respectively.Detailed chemical reaction mechanism model was applied to describe processes of chemical detonation reactions.The contours of pressure,temperature,distribution of OH mass fraction as well as numerical cellular patterns were obtained.Results show that,along the concave wall,the pressure,temperature and the chemical reaction intensity affected by convergence and divergence are higher than those along the convex wall while detonation wave spreading in circular tube,and the size of cellular pattern is smaller than that along the convex wall.The propagation velocity along the concave wall is higher than that along the convex wall.The calculated results accord with the measured results qualitatively.