Schur-complement multigrid

Summary.A Schur-complement multigrid method for the solution of convection-diffusion problems with strongly discontinuous coefficients is the focus of this paper. This algorithm turns out to be robust and efficient for our test problems. Its convergence rate is in all cases superior to the standard multigrid method. The Schur-complement multigrid method is applied to the problem of the decontamination of a heterogeneous porous medium by flushing. We determine the typical decontamination time for several configurations and its functional dependence on the statistical properties of the hydraulic conductivity distribution of the medium.