关键词: 计算流体力学, 动态网格, 网格变形, Delaunay图, 运动边界, 扑翼

Abstract:

The dynamic mesh deformation method based on Delaunay graph mapping is noniterative and is therefore efficient for unsteady flow solutions. However, intersections occur occasionally between the background graph elements for complex geometries with large relative movements. It not only consumes more time but also deteriorates mesh quality to regenerate the graph and to relocate grid points. Therefore, a dynamic mesh generation method based on double Delaunay graph mapping is proposed. A virtual and a true background graphs in conjunction with a virtual and a true mappings are generated by appending some assistant points in the initial graph. The assistant points and grid points move according to the virtual graph and virtual mapping, the true graph and true mapping respectively. The results of flapping-wing cases indicate that the double graph mapping method absolutely avoids the problems caused by the intersections of graph elements and shows dramatic improvement of mesh quality, efficiency and robustness for complex problems with moving boundaries.

Key words: CFD,  , dynamic , mesh,  , grid , deformation,  , Delaunay , graph,  , moving , boundary,  , flapping-wing