Abstract: | The solution of the incompressible Navier-Stokes equations in general two- and three-dimensional domains using a multigrid method is considered. Because a great variety of boundary-fitted grids may occur, robustness is at a premium. Therefore a new ILU smoother called CILU (collective ILU) is described, based on r-transformations. In CILU the matrix that is factorized is block-structured, with blocks corresponding to the set of physical variables. A multigrid algorithm using CILU as smoother is investigated. The performance of the algorithm in two and three dimensions is assessed by numerical experments. The results show that CILU is a good smoother for the incompressible Navier-Stokes equations discretized on general non-orthogonal curvilinear grids. |