AGGLOMERATION MULTIGRID FOR 2-DIMENSIONAL VISCOUS FLOWS

Agglomeration multigrid, which has been demonstrated as an efficient a nd automatic technique for the solution of the Euler equations on unst ructured meshes, is extended to Viscous turbulent flows. For diffusion terms, coarse grid discretizations are not possible, and more accurat e grid transfer operators are required as well. A Galerkin coarse grid operator construction and an implicit prolongation operator are propo sed. Their suitability is evaluated by examining their effect on the s olution of Laplace's equation. The resulting strategy is employed to s olve the Reynolds-averaged Navier-Stokes equations for aerodynamic flo ws. Convergence rates comparable to those obtained by a previously dev eloped non-nested mesh multigrid approach are demonstrated, and sugges tions for further improvements are given.