A Fast Preconditioned Iterative Solver for Unsteady Incompressible Flow Problems

This paper is concerned with the solution of unsteady incompressible flow problems using Marker and Cell finite difference discretizations and preconditioned Krylov subspace methods. Our emphasis is on the preconditioner that can be thought of a new splitting of the discretized equations. The preconditioner we focus on is the variation from the Hermitian and Skew-Hermitian (HSS) Splitting preconditioner. Such an preconditioner for the unsteady Oseen (linearized Navier -- Stokes) problems in two or three dimensions are described and experimentally compared.