ハイブリッド非構造格子に対するスペクトラルボリューム法の格子収束性に関する研究

抄録

Grid convergence characteristics of the spectral volume (SV) method is explored for hybrid unstructured meshes. In this study, the SV method originally developed for tetrahedral computational cells is extended to use prismatic and hexahedral cells. The extended SV method (hereafter SV⁺) for hybrid unstructured mesh is first applied to solve the linear advection and diffusion problems. The formal spatial accuracy is rigorously kept in both problems. Then, the SV⁺ is applied to solve the turbulent boundary layer flow over a flat plate. It is shown that the SV⁺ can obtain grid convergence even for using tetrahedral cells in the turbulent boundary layer, where the mesh aspect ratio becomes as large as 20,000. Convergence toward steady solutions using prismatic layers with the same number of DOFs becomes about two times faster than that using tetrahedral cells in the turbulent boundary layer. Finally, the SV⁺ is applied to compute the flowfield around the NASA-CRM. It is shown that the present SV⁺ gives mesh converged solutions which quantitatively agree with the corresponding experimental data regardless of mesh type.