潜水面变动的空间四面体单元网格自动生成方法

Automatic generation algorithm of tetrahedral element mesh for considering movement free groundwater table

提出了一种由平面三角网格自动生成三维空间四面体单元网格的方法,其基本思路是将含水层平面分成三角形单元网格,将每个三角形沿垂直方向对应一个三棱柱,作为最初的三棱柱;依次将每个三棱柱按照潜水面位置和分层信息划分成不同数目的四面体,从而生成三维空间四面体单元网格。剖分结果表明,此方法综合考虑了潜水面的位置和各含水层顶底板的起伏情况,能够简洁地生成层面起伏的空间四面体网格,特别适用于刻画潜水面波动、含水层顶底板起伏和存在透镜体或岩性缺失等含水层结构复杂的情况下,自动地剖分并生成单元信息,为三维计算的实现奠定了基础。

In this paper, a new approach of automatic generation of 3-D tetrahedral element mesh based 2-D triangle mesh is presented. The key principle of the algorithm is that the original prismatic polyhedron is formed by planer triangular mesh crossed with vertical section, and then divided into several tetrahedral elements according to the information parameters zonation in aquifers. The moving free groundwater table is also taken into account during the course of mesh generation in each calculation step.The programming procedure of tetrahedral meshing is also stated in detail in the paper. It is concluded that the algorithm is a valid, effective and convenient approach to the description of spatial stratum formation in complex aquifer such as lens or sharp lithofacies and etc, so as to provide 3-D mesh data for numerical calculation.