Implicit solution of preconditioned Navier-Stokes equations using algebraic multigrid

We describe an algorithm for the solution of the Navier-Stokes equations on unstructured meshes that employs a coupled algebraic multigrid method to accelerate a point-implicit symmetric Gauss-Seidel relaxation scheme. The equations are preconditioned to permit solution of both compressible and incompressible Bows. A cell-based, finite volume discretization is used in conjunction with Bus-difference splitting and a linear reconstruction of variables. We present results for flowfields representing a range of Mach numbers and Reynolds numbers. The scheme remains stable up to infinite Courant number and exhibits CPU usage that scales linearly with cell count.