Three dimensional anisotropic adaptation of unstructured volume grids based on edge refinement along directions of adaptation

摘要

The approach to anisotropic adaptation of unstructured volume grids is developed and applied to numerical solutions of convection-diffusion and Euler equations. The grid adaptation is based on edge refinement along prescribed directions defined locally by monitor function. 3D reconnection aligns edges to contour levels of this function. The weighted sum of the first and second order derivatives along the edge is utilized as interpolation based edge error indicator. The grid adaptation technique was applied to convection-diffusion problem modeling the 3D shear layer and to transonic Euler flow calculation around isolated wing. The Discontinuous Galerkin method with various order basis functions (k=0, 1, 2) was employed in numerical solution of convection-diffusion problem. The comparison of convergence properties for uniform, isotropic and anisotropic adaptations are made. The obtained convergences for Discontinuous Galerkin schemes of different order of accuracy have good correlation with the theoretically predicted values.