基于Delaunay背景网格插值技术的动态网格生成方法无需迭代计算，效率较高。但对复杂构形大幅运动的动边界问题，尤其当边界大幅转动时，背景网格极易交叉重叠。重新生成背景网格和重新定位网格节点信患不仅费时而且会导致网格质量的严重下降。本文提出改进的基于背景网格的动态网格变形方法，通过在初始Delaunay背景网格中添加辅助点，生成一层新的背景网格和新的映射关系；采用ball-vertex弹簧法驱动新背景网格的变形，进而牵动目标网格的变形。算例表明，本文提出的动态网格变形方法对所关心区域的网格具有良好保形性，边界可转动更大角度而不会出现网格交叉重叠问题，总体上提高了动态网格更新的效率和质量。%The dynamic mesh deformation method based on Delaunay graph is non-iterative and therefore efficient. However, inter-sections occur occasionally between the background graph elements for complex geometries with large relative movements , especially for the large boundary rotations. It not only consumes more time but also deteriorates mesh quality to regenerate the graph and to relocate grid points. In this work ,a dynamic mesh generation method based on background grid morphing is proposed. By ap- pending some assistant points in the initial graph, a new background graph in conjunction with a new mapping is generated. Then, the Ball-Vertex method is employed to move the new graph which drives the deformation of the object mesh. Some cases demonstrate that the improved method have better ability of keeping the shape for the regions concerned and can improve the intersection problems even with large boundary rotations. In general,the method proposed shows better performance in mesh quality and efficiency.
展开▼
