大幅运动复杂构形扑翼动态网格生成的一种新方法

 基于Delaunay图映射的动态网格生成方法无需迭代计算，效率高，稳定性好。但对大幅运动复杂构形的动边界问题，背景图容易交叉，重新生成背景图和重新定位网格点信息不仅费时而且会导致网格质量的严重下降。提出一种双重Delaunay图映射的动网格生成方法，通过在初始背景图中添加辅助点，生成虚实两种背景图和虚实两种映射关系。分别根据虚映射关系和虚背景图、实映射关系和实背景图，移动辅助点和网格点。几个复杂构形的扑翼算例表明，双重图映射方法多付出极少的内存代价即可避免背景图交叉引起的问题，提高了动网格生成的效率和质量，增强了处理大变形复杂动边界问题的强健性。

A New Dynamic Mesh Generation Method for Large Movements of Flapping-wings with Complex Geometries

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.