组合的LU分解迎风方法的多重网格收敛

为提高计算收敛速度，以新的高收敛率的LU型隐式格式和高精度、高分辨率的MUSCL TVD迎风格式为基础，对可压缩无粘和粘性流动问题计算的多重网格方法进行了探讨。采用二维凸包通道和VKI LS 59跨音速透平叶栅为算例，通过与单网格上的计算迭代性能做对比，证明这种算法在原有基础上更大幅度地提高了计算收敛速度，节省了CPU时间，而且方法本身也简单易行。

Multigrid convergence of a combined LU-factored upstream method

To effectively improve the computational convergence rate, a multigrid acceleration technique based on a new lower upper (LU) implicit scheme and a fourth order high resolution MUSCL TVD scheme has been developed for solving the governing equations for compressible inviscid and viscous flows. The computations have been performed for a two dimensional passage with convex surface and for a two dimensional VKI LS 59 transonic turbine cascade. Compared with experimental data and results from a single grid numerical scheme, these solutions demonstrate both the efficiency and accuracy of the present algorithm for simulating inviscid and viscous compressible flows. Despite the additional computational effort required in the multigrid cycling, the superior convergence is shown to result in significantly reducing overall CPU times.