三维分块非结构化网格上的可压缩流计算方法

提出了分块非结构化网格生成方法,通过子块划分、子块网格划分、整体网格拓扑连接生成可局部加密的分块非结构化网格,既具备了非结构化网格对复杂区域的处理能力,又避免了分块结构化网格块间信息传递的复杂计算过程.通过将密度修正值引入压力修正方程,发展了非结构化网格上可压缩流动的SIMPLE算法.对孤立翼型及透平叶栅的流动进行了数值计算,压力系数、速度、折转角的数值结果与已有的实验值吻合较好,验证了数值方法的精度.

Numerical method of compressible flow on three-dimensional sub-block unstructured grid

A numerical method for the calculation of internal flow in turbomachinery is developed. Firstly, the sub-block unstructured grid generation method is proposed. The complex multiple-connected flow domain is divided into several simple single-connected sub-blocks, and then each sub-block is discretized into body-fitting meshes, finally, each sub-block grid is united to form a whole grid whose topological connection information is saved by unstructured grid manner. The sub-block unstructured grid not only has the advantage of unstructured grid to deal with the complex domain, but also avoid the disadvantage of multi-block grid to treat the complicated flow field variable transfer on the interface between sub-blocks. Secondly, a three dimensional compressible SIMPLE (semi-implicit method for pressure linked equation) algorithm on sub-block unstructured grid is developed by including the density correction term in the pressure correction equation. Finally, the proposed methods are used to numerically solve the flow fields around an isolated airfoil and in a turbine cascade. The accuracy of the method is validated by the good agreement between the numerical results with the experimental data. This work is of theoretical significance and applied value to develop the numerical method for solving the complicated internal flow in turbomachinery.