PARALLEL MULTIGRID COMPUTATION OF THE UNSTEADY INCOMPRESSIBLE NAVIER-STOKES EQUATIONS

Parallel computation on distributed-memory machines offers the capabil ity of a scalable approach to the solution of large CFD problems. Howe ver, in order to fully realize this capability, it is necessary not on ly to devise parallel methodologies, but also to develop numerical sch emes for which the computational effort also scales with problem size. To this end, a parallel multigrid scheme for the calculation of the u nsteady incompressible Navier-Stokes equations is considered here. A s patial and temporal second-order accurate implicit discretization sche me on a staggered grid is employed, and a full approximation storage m ultigrid method, appropriate for nonlinear problems, is used. A parall el solver is developed which smooths the equations at each multigrid l evel in a fully coupled mode. The programming paradigm is single progr am multiple data with message passing. In comparison with single-grid calculations, it is demonstrated that the convergence rate for multigr id calculations is considerably superior and dominates the slight degr adation in speed up. (C) 1996 Academic Press, Inc.