Adaptive hexahedral mesh generation based on local domain curvature and thickness using a modified grid-based method

This paper presents an adaptive hexahedral mesh generation algorithm for three-dimensional models. It is based on the conventional grid-based method and geometry-adaptive technique to generate uniformly sized or locally refined hexahedral meshes. The first step is to construct the refinement information fields of the source points and the corresponding elements according to the surface curvature of the solid model. A thickness refinement criterion is then used to construct the thickness-based refinement information field of elements from digital topology. Secondly, the element refinement fields are integrated and modified according to the conformal refinement templates proposed in this paper, and used as a metric to generate an initial grid structure enveloping the solid model completely. In order to ensure the conformity of the generated mesh, a set of new refinement templates are proposed, and the corresponding modes for converting arbitrary refinement fields to the templates is established. Especially two kinds of new transition templates, which avoid the propagation of the refinement field, are added. Hexahedral element meshes capturing all the geometry characters of the solid models are generated. The effectiveness and robustness of the algorithm are tested through the applications in several complex three-dimensional models.