适用于可压缩和不可压缩流动的NS方程预处理数值解法

Suitability of preconditioning numerical method on NS equations for Compressible and imcompressible flows

该文在多块耦合隐式求解方法的基础上,在不可压缩流动NS方程求解器中引入了双层一时间迭代的预处理计算方法,使离散方程组的各个特征值之间互相平衡,降低了可压缩流动NS求解器中低速流动时的刚性,提高了数值方法对低速流动的适应能力,通过Re=20,40时圆柱绕流的计算结果与试验数据验证,得到了数值结果误差小于5%的工程允许范围。

A preconditioning method is introduced to the NS solver based on the dual-time iteration for calculating unsteady compressible flows. The eigenvalues of discrete equations may be balanced in this method. The stiffness of compressible NS solver can be reduced for low-speed flow and the capability of the solver may be increased for low-speed flow. By comparing the Numerical results for the flow around cy the cylinder at Re=20, 40 with the experimental data, a good agreement was obtained with a discrepancy of about 5%.