基于有限差分非规则边界网格剖分技术

Mesh Generation Method of Irregular Boundary Regions Based on FDM

有限差分法广泛用于铸造过程中流场和温度场的模拟,而对复杂实体进行更为准确、快捷的三维网格划分对铸造过程模拟十分重要。本文在传统FDM结构化网格剖分算法基础上,开发出对实体边界区域采用20点坐标定义的不规则凸多面体网格进行离散的非规则边界网格剖分程序。剖分实例证明,这种剖分算法可以为大型、复杂的铸件铸造过程数值模拟提供更为准确的计算网格,可有效地消除传统有限差分剖分算法阶梯型边界网格近似边界区域所引起的计算误差。

The FDM （finite difference method） is widely used in the simulation of flow field and temperature field in the casting process, and more accurate, fast mesh generation for complex entities is important during the simulation. Based on the traditional FDM mesh generation, the codes for FDM mesh generation of irregular boundary regions of castings were developed, in which boundary regions are discretized to irregular convex polyhedron grids defined by 20 point coordinates. Examples of mesh generation shows that the subdivision algorithm provides more accurate computational grids for the numerical simulation for the die casting process of large, complex castings, and also could effectively eliminate the calculation error caused by the step-type boundary grids approximation of the boundary regions.