A digraph-based hexahedral meshing method for coupled quasi-polycubes

Sub-mapping is recognized as the most commonly used method for generating structured hexahedral mesh which has become a prior choice for mechanical simulation. However, volume decomposition process of sub-mapping, due to the diversity of entity structures, still lacks support from stable algorithm. Moreover, as a preprocessing step of sub-mapping, morphing process sometimes leads to unsatisfactory mesh quality. In order to improve stability and meshing quality of sub-mapping, a digraph-based structured hexahedral meshing method for coupled quasi-polycubes is proposed in this paper. The method avoids the processes of volume decomposition and morphing. At first, an initial manual decomposition is carried out. The input model is decomposed into a number of sub-entities with respect to which initial digraphs are built. Secondly, virtual edges and vertices are constructed by means of mean value interpolation and then added into its corresponding digraph, so as to build connections between subgraphs within one digraph. Thirdly, face sheets are obtained by intersecting sub-entities with one another. Vertices and edges of the face sheets are added into their corresponding sub-entities’ digraphs to establish connections between digraphs of sub-entities. Finally, a linear system is constructed according to the solution of which the whole model is meshed. Experiments revealed in this paper demonstrate that the proposed method is applicable for all-structured hexahedral mesh generation of coupled quasi-polycubes.