Generation Method Of Structured Quadrilateral Mesh Based On Domain Decomposition

At present,numerical analysis methods have been widely used in various scientific calculations and engineering analysis,and are playing an increasingly important role.When applying the numerical analysis method,the analysis model needs to be discretized firstly,that is,the mesh is divided.Since the emergence of mesh division technology,there has been a considerable development of many commercial software.However,some engineering analysis fields have special requirements on the type and quality of mesh,and the existing mesh division methods are difficult to meet the requirements of numerical analysis,so it is necessary to carry out a specific study on them and propose the corresponding mesh division algorithm.Mesh division methods are mainly divided into structured mesh division and unstructured mesh division.Structured mesh shape rules,the mesh quality is higher.For some numerical analysis fields,the use of structured mesh,the direction of the mesh is consistent with or perpendicular to the direction of the boundary of the analysis area,is conducive to improving the accuracy of the analysis results,so structured mesh is the preferred mesh for this kind of numerical analysis.According to the special requirements of mesh in some application fields,this paper studies the method of structured mesh generation,and proposes a mesh generation algorithm based on regional decomposition,which can generate structured quadrilateral meshs in complex regions and meet the needs of structured mesh generation in these fields.In this paper,the quadrilateral structural mesh generation on the tire surface is studied.According to the characteristics of more surface areas,complex structure and multiple connected domains,a method of automatic decomposition of the region is proposed to generate a structured quadrilateral mesh on the tire surface.Firstly,the multi-connected domain is transformed into simply connected domain,the structured quadrilateral meshes are generated in the sub-regions,and finally the meshes of all regions are merged to obtain the mesh of the whole region.In order to satisfy the mesh matching between adjacent regions and the constraint conditions of the number of nodes in each region,a linear programming method is proposed in this paper to automatically adjust the number of boundary nodes so as to generate a structured quadrilateral mesh in the region.The regional decomposition method proposed in this paper can reduce the tedious manual processing and improve the quality and efficiency of tire model mesh generation.For river models,the boundary shape is usually tortuous and the curvature varies greatly.When the existing meshing software is used to generate the river model,the mesh quality is poor due to the unreasonable generation of boundary nodes.Aiming at the problem of mesh generation in river model,this paper proposes a method to automatically adjust the position of boundary nodes,which can effectively improve the quality of mesh generation.This paper also studies the generation of structured quadrilateral meshes on the surface of 3d models.Due to the complex surface shape of the 3d model,it is difficult to directly generate a structured mesh on its surface,and the mesh quality is difficult to be guaranteed.In order to reduce the difficulty of generating a structured mesh,a method of mapping a three-dimensional surface onto a two-dimensional surface to generate a mesh is proposed.In this paper,the geometric processing of the surface of the 3d model and the method of mesh generation are proposed,including the determination of sub-surface and feature edges,the discretization of boundary,the transformation of multiple connected domains,the mapping of the surface of the 3d model,the generation of the planar mesh and the mapping of the 3d surface mesh.The method of region decomposition proposed in this paper can generate structured quadrilateral meshes on three-dimensional surface,which reduces the difficulty of meshes generation.In this paper,the quadrilateral structured mesh generation method proposed in this paper,the corresponding algorithm and program are developed.The application of the developed program to the mesh generation of tire surface,river model and 3d model surface proves the reliability of the proposed method.