Efficient fully-coupled solution techniques for two-phase flow in porous media - Parallel multigrid solution and large scale computations

This payer is concerned with the :Fast resolution of nonlinear and linear a lgebraic equations arising from a fully implicit finite volume discretizati on of two-phase flow in porous media. We employ a Newton-multigrid algorith m on unstructured meshes in two and three space dimensions. The discretized operator is used for the coarse grid systems in the multigrid method. Prob lems with discontinuous coefficients are avoided by using a newly truncated restriction operator and an outer Krylov-space method. We show an optimal order of convergence for a wide range of two-phase flow problems including heterogeneous media and vanishing capillary pressure in an experimental way . Furthermore, we present a data parallel implementation of the algorithm w ith speedup results. (C) 1999 Elsevier Science Ltd. All rights reserved.