AN ADAPTIVE AGGLOMERATION METHOD FOR ADDITIVE CORRECTION MULTIGRID

In the computational simulation of uid ow and scalar transport, multigrid iterative solution techniques often fail or stall when the discrete linearized equations have strongly anisotropic coe cients. In the present work, an adaptive agglomeration algorithm for forming coarse grids is presented that allows multigrid techniques to work e ciently for equation sets with anisotropic coe cients. The adaptive agglomeration is de ned by two rules and several guidelines that follow from a physical interpretation of the performance of iterative solvers like Gauss{Seidel. The e ectiveness of the adaptive agglomeration algorithm is demonstrated for a wide range of test cases