Multiblock multigrid grid generation algorithms: Overcoming multigrid anisotropy (Q1368929)

Multiblock multigrid algorithms for the generation of boundary-fitted grids (BFGs) are presented which avoid undesired multigrid anisotropy. The algorithms combine a domain decomposition technique, the elliptic grid generation and the multigrid computation to provide fast convergence. Anisotropy is identified as an undesirable multigrid effect and is overcome by investigation over coefficients of the generating systems. They can provide information to select appropriate relaxation algorithms. Visualizations of 2D and 3D computed grids and displays of convergence histories are shown.