A Decoupled Preconditioning Technique for a Mixed Stokes-Darcy Model

We propose an efficient iterative method to solve the mixed Stokes-Dracy model for coupling fluid and porous media flow. The weak formulation of this problem leads to a coupled, indefinite, ill-conditioned and symmetric linear system of equations. We apply a decoupled preconditioning technique requiring only good solvers for the local mixed-Darcy and Stokes subproblems. We prove that the method is asymptotically optimal and confirm, with numerical experiments, that the performance of the preconditioners does not deteriorate on arbitrarily fine meshes. Mathematics subject classifications (2010): 65M12, 65M15, 65M60, 35M10, 35Q35, 76D07, 76S05