Adaptive techniques for unstructured nested meshes Original Research Article

The purpose of this paper is twofold. First we introduce improved versions of our algorithms for refining and coarsening 2D and 3D nested triangular and tetrahedral grids, and secondly the application of these algorithms in the simulation of 2D and 3D problems, is demonstrated. A key idea of the algorithms is the use of the topological concept of the skeleton of a triangulation in two or three dimensions in order to reduce the dimension of the refinement problem in a natural hierarchic manner. Improved skeleton based refinement (SBR) algorithms and their counterpart, the skeleton based derefinement (SBD) algorithms are described in this study. The algorithms are fully automatic and are applied here to a 2D boundary value problem, a 3D approximation problem with a large gradient, a geometric shape modeling problem and a simulation evolution problem in 3D.