A Strong Coupled Agglomeration Multigrid for Navier-Stokes Equations on 3D Hybrid Grids

This paper focused on a series of agglomeration multigrid techniques for the numerical solution of the 3D Reynolds Averaged Navier-Stokes equations on cell-centered hybrid grids, which conform with finite volume discretization scheme. After investigation isotropic and semi-coarsened agglomeration strategy versions depending on grid stretching, we explore a new agglomeration algorithm to automated generate coarse grids for multigrid methods, which can conduct to 2D/3D unstructured and hybrid grids. The algorithm based on face normal weighting, fuse the strongest coupled neighbor face to form a new cell in coarsen grid once at a time. In order to achieve the coarsening ratio approximately 4 in 2D and 8 in 3D grids, the process should be repeated. The numerical results which conducted on NACA0012 airfoil on 3D indicate that nearly optimal convergence rates and computational complexity, this method also shows better complexity than the listed method owing to the better quality of the coarse grid. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of [CEIS 2011]