非结构动网格生成的弹簧-插值联合方法

Spring-interpolation Approach for Generating Unstructured Dynamic Meshes

提出了基于弹簧法的两点改进,以解决边界发生大变形时的非结构网格变形问题。为了使边界运动引起的网格变形能更好地由边界传递到内部网格中,提出了一种新的基于Delaunay网格插值的弹簧倔强系数逐层改进方法。为了提高弹簧法的计算效率,引入背景网格和直接插值方法,提出了弹簧-插值法。弹簧-插值法首先生成计算域的背景网格(粗网格),然后由弹簧法求解边界运动引起的背景网格变形,最后利用变形后的背景网格直接插值得到计算网格的变形。算例结果表明:改进后的方法一方面有效地提高了动网格的变形能力和变形后的网格质量;另一方面通过降低弹簧法的求解规模,显著地提高了动网格的变形效率。

The article presents two improvements on the spring analogy for unstructured mesh deformation in engineering applications in which large boundary motions are encountered.A gradually updating scheme which generates gradient spring stiffness by the interpolation method on Delaunay graph is proposed to improve the deformation spread.The spring-interpolation approach is proposed to improve the efficiency of the spring ana-logy.The approach first generates a background mesh （coarse mesh） of the solution domain.Then the defor-mation of the background mesh caused by boundary movements is solved by a spring analogy.Finally,the deformation of the computational mesh is obtained by an interpolation method on the background mesh.Examples demonstrate that the presented method significantly improves the deforming ability of meshes as well as the mesh quality after deformation.Additionally,examples also show that the proposed approach improves the efficiency of mesh deformation effectively by reducing the order of the equations of the spring analogy.