高阶熵条件格式下Euler方程与 N-S方程的混合算法

针对在工程问题中使用N-S方程计算量大的问题,提出只在粘性作用显著的局部区域求解N-S方程,在流场的其余部分采用Euler方程计算的办法来模拟具有复杂外形的流动问题,并提出了一种基于高阶熵条件格式的算子分裂算法.应用所构造的算法对绕迫击炮弹的亚、跨超声速流动进行了模拟计算.计算结果与试验数据的对比表明,所提出的方法是切实可行的. 

High Order Entropy Condition Scheme for Mixed Euler/N-S Equations

In order to circumvent the problem of a huge amount of computing time required for solving viscous flows over bodies with complicated configuration using N-S equations, a mixed Euler/N-S solver was proposed. The solver is capable of preserving sufficient accuracy by using N-S equations in the flow field where viscous effects emerge as the dominant factor and employing Euler equations in the remaining regions. The primary scheme was constructed based on a high order entropy condition algorithm, in conjunction with an operator splitting concept deduced from theory of semi-group. The developed method was used to simulate subsonic, transonic as well as supersonic flows over a mortar configuration. The numerical results were compared favorably with experimental data.