  We consider the use of multipreconditioning to solve linear systems when more
than one preconditioner is available but the optimal choice is not known. In
particular, we consider a selective multipreconditioned GMRES algorithm where
we incorporate a weighting that allows us to prefer one preconditioner over
another. Our target application lies in the simulation of incompressible
two-phase flow. Since it is not always known if a preconditioner will perform
well within all regimes found in a simulation, we also consider robustness of
the multipreconditioning to a poorly performing preconditioner. Overall, we
obtain promising results with the approach.

Numerical Analysis;Numerical Analysis