欧拉方程隐式迭代矢通量分裂跨音流场计算

TRANSONIC FLOW CALCULATION OF EULER EQUATIONS BY IMPLICIT ITERATING SCHEME WITH FLUX SPLITTING

本文用矢通量分裂格式的有限体积法求解时间相关欧拉方程组。文中证明,矢通量分裂的有限体积法不能再采用物面反射边界条件。二维问题用隐式迭代法解代数方程组,第三维方向上则用强隐格式往返扫描。此法CFL数可达100的数量级,收敛快,占内存少。跨音流场计算结果与实验符合良好,激波只占一两个网格。

Three dimensional Euler equations are solved in the finite volume form with Van Leer's flux vector splitting scheme. Block matrix is inverted by Gauss-Seidel iteration in two dimensional plane while strongly implicit alternating sweeping is implemented in the direction of the third dimension. Very rapid covergence rate is obtained with CFL number reaching the order of 100. The memory resources can be greatly saved too. It is verified that the reflection boundary condition can not be used with flux vector splitting since it will produce too large numerical dissipation. The computed flow fields agree well with experimental results. Only one or two grid points are there within the shock transition area.