On 3D Anisotropic Local Remeshing for Surface, Volume and Boundary Layers

Abstract

A simple strategy for generating anisotropic meshes is introduced. The approach belongs to the class of metric-based mesh adaptation procedures where a field of metric tensors governs the adaptation. This development is motivated by the need of generating anisotropic meshes for complex geometries and complex flows. The procedure may be used advantageously for cases where global remeshing techniques become either unfeasible or unreliable. Each of the local operations used is checked in a variety of ways by taking into account both the volume and the surface mesh. This strategy is illustrated with surface mesh adaptation and with the generation of meshes suited for boundary layers analysis.

Two simple mesh operators are used to recursively modify the mesh: edge collapse and point insertion on edge. It is shown that using these operators jointly with a quality function allows to quickly produce an quality anisotropic mesh. Each adaptation entity, ie surface, volume or boundary layers, relies on a specific metric tensor field. The metric-based surface estimate is used to control the deviation to the surface and to adapt the surface mesh. The volume estimate aims at controlling the interpolation error of a specific field of the flow. The boundary layers metric-based estimate is deduced from a level-set distance function.