双时间步长加权ENO-强紧致高分辨率格式及在叶轮机械非定常流动中的应用

在非结构网格下,针对非定常三维N-S方程组发展了一种双时间步长高精度快速迭代格式。该格式在时间上具有二阶精度,在空间上将r=3的加权ENO格式与强紧致格式相结合去处理N-S方程中的对流项以及离散方程的右端项,并用四阶精度的紧致格式去计算N-S方程中的粘性项。典型的3个算例从不同侧面对格式进行了考核。计算表明:该算法具有高效率与高分辨率的特征,所得的计算结果与相关实验数据比较吻合,初步表明了该算法可以在非结构网格下模拟非定常流动的物理过程。 

Pseudo-Time Method of Weighted ENO-Strongly Compact High Resolution Schemes and Its Application to Turbomachinery Unsteady Flow

The Pseudo-time Method and high accuracy rapid iterative scheme were developed for unsteady 3D N-S equations with unstructured grids.This scheme has two-order accuracy in time,and combines weighted ENO scheme (r=3) and strongly compact scheme to treat convection term in N-S equation and the right terms of the discrete equation.Besides,four-order accurate strongly compact scheme is used to calculate viscosity term of N-S equation.Three typical cases were used to check the scheme in different ways.Numerical test shows that the scheme not only has the character of high efficiency and high resolution,but also can keep high-order accuracy.Further,the computed results obtained from the proposed scheme are in good agreement with experiment and show the scheme can simulate physical process of unsteady flow with unstructured grids.