Roe格式在多组元燃烧流场数值模拟中的应用

Numerical Simulation of Multi-component Reacting Flow Using Roe Scheme

对Roe通量分裂格式进行了详细讨论,并将其推广应用到基于非结构网格的高超声速多组元燃烧流场的数值模拟中。控制方程采用三维多组元Euler方程,重点针对Roe格式开展研究;考虑到燃烧流场求解过程中出现的刚性问题,对化学反应源项采用点隐式方法处理。对超声速条件下钝头体激波诱导燃烧流场进行了数值模拟,比较分析了3种经典化学动力学模型对流场结构的影响,获得与数值模拟、试验数据相符的结果。结果表明发展的方法可以用于多组元燃烧流场的数值分析,且化学动力学模型的选取直接影响激波诱导燃烧流场中诱导区厚度。

A Roe approximate Riemann solver-based scheme for calculating hypersonic multi-component chemically reacting flow is discussed.The governing equations are multi-component three-dimensional Euler equations.The spatial distribution is discretized using the Roe flux difference splitting scheme.The code is marched in time by the point implicit procedure,which is used to couple the chemical kinetics source term and fluid dynamics.The stiff problems of ordinary differential equations are solved by an implicit formulation over a characteristic time scale of fluid.To verify the current approach,the proposed method is used to simulate a decoupled shock-deflagration system.Three classic chemical kinetics models are discussed.Numerical results agree well with other experimental results or numerical results,which shows that in hypersonic reacting flow,the Roe scheme has high accuracy in shock wave or combustion front capturing capability and the chemical kinetics model plays a critical role in the simulation of multi-component reacting flow.