Abstract: The effects of grid aspect ratio on the efficiency of implicit multigrid method have been analysed theoretically. The results indicate that the algorithm affects convergence on highly stretched or non unifirm grids. The improvement ways are introduced, and the validations are also been discussed. Finally the comparison of convergence between the original model and the improved one is presented.

Key words: implicit multigrid method, realistic aerodynamic configuration, grid aspect ratio, dissipation model