Tetrahedral mesh generation for environmental problems over complex terrains

Abstract

In the finite element simulation of environmental processes that occur in a three-dimensional domain defined over an irregular terrain, a mesh generator capable of adapting itself to the topographic characteristics is essential. The present study develops a code for generating a tetrahedral mesh from an ”optimal” node distribution in the domain. The main ideas for the construction of the initial mesh combine the use of a refinement/derefinement algorithm for two-dimensional domains and a tetrahedral mesh generator algorithm based on Delaunay triangulation. Moreover, we propose a procedure to optimise the resulting mesh. A function to define the vertical distance between nodes distributed in the domain is also analysed. Finally, these techniques are applied to the construction of meshes adapted to the topography of the southern section of La Palma (Canary Islands).