INTERPOLATION-FREE SPACE-TIME REMESHING FOR THE BURGERS-EQUATION

In this paper we present a mesh management strategy for use with disco ntinuous-Galerkin space-time finite element formulations of flow probl ems. We propose a refinement technique for simplex-type meshes which r equires no interpolation between grids at slab interfaces. The strateg y uses an a posteriori spatial error estimator to tag refinement or co arsening. Orientation of element edges along how characteristics is ac complished by nodal displacement, and by a new diagonal-swapping techn ique to correct for the effects of misalignment due to h-refinement. T he swapping procedure realigns the mesh to improve the effectiveness o f the h-adaptive process. Results are presented for the Burgers Equati on using large time steps on a problem which exhibits merging and stee pening fronts. (C) 1997 John Wiley & Sons, Ltd.