Abstract: The preprocessing module of numerical simulation includes CAD modeling, meshing, load and boundary condition processing. It is worth noting that high-quality meshes are essential for high accuracy and reliable simulation results. However, mesh generation is still a bottleneck in numerical simulation. To resolve the difficulties of mesh generation associated with the numerical simulation, an adaptive unstructured mesh generation algorithm for arbitrary geometry with proximity features is presented. The binary-tree subdivision is carried out based on the mesh size, surface curvatures, thickness distribution, and other geometry features. The geometry fitting techniques and the nearest distance methods are adopted to approximate the solid boundary of the mesh nodes. In order to effectively construct the core hexahedral mesh, a fast intersection algorithm between topological elements and solid model boundary is established, which improves the efficiency of intersection calculation. For complex entities with proximity characteristics, a new type of adjacent feature template is innovatively proposed, which successfully solves the problem of entity boundary fitting of the traditional outside-in mesh method. Numerical examples show that this method has the ability to generate almost hexahedral element mesh for complex geometry with proximity features and critical regions are expressed accurately, and global mesh is distributed with rationality and high quality.

Key words: binary tree, proximity geometric features, unstructured grid, solid boundary fitting