快速生成三维非结构网格的一种方法

An efficient method for generation of three dimensional unstructured grid

提出了快速生成三维非结构网格的一种方法。在（ｘ１，ｘ２，ｘ３）构成的三维曲线坐标系中，该方法只需在任意选定的一个拟Ｓ１面（即由ｘ１，ｘ２所张成的曲面）上生成非结构网格，而其它拟Ｓ１面上的网格是通过空间映射来完成的。所生成网格的总特点是在拟Ｓ１面上为非结构三角形网格，而沿ｘ３方向上具有结构网格的特征，因此，所生成的网格属于五面体单元。在拟Ｓ１面上生成网格时，采用分区生成技术，即在近壁面区生成以Ｏ型网格为基础的三角形单元，在远离壁面区采用本文发展的一种高效快速生成非结构网格的方法。该方法改进了Ｂｏｗｙｅｒ－Ｗａｔｓｏｎ算法，通过合理的配置网格尺度分布函数来保证整个拟Ｓ１面上非结构网格生成的质量，并借助于堆栈搜索技术，大大提高了计算效率。整个三维程序用Ｆｏｒｔｒａｎ语言编制，大量的计算表明：该程序能够快速高效地生成满意的三维非结构网格。

A high performance algorithm for generation of three dimensional unstructured grid was presented. Unstructured grids were generated on one given S 1 surface (i.e. a surface of constant x 3 in a three dimensional curved coordinate ( x 1,x 2,x 3 )), while the grids on the other S 1 surfaces were constructed by a space mapping. The final grids obtained in this way were unstructured on S 1 surfaces and structured in x 3 direction, and therefore is composed of pentahedrons. In the generation of the grid on the S 1 surface the triangle elements of O type grid were created near the walls. By improving Bowyer Watson method, a scheme of high efficiency was developed to produce unstructured grids in the region far from the walls. The quality of the grids on the S 1 surface was ensured by a more appropriate grids scale function and the computation was greatly accelerated by the stack searching method. Several examples show that the present code (written in Fortran) can generate satisfactory three dimensional unstructured grids at a high speed.