Multigrid acceleration of a block structured compressible flow solver

We study a multiblock method for compressible turbulent flow simulations and present results obtained from calculations on a two-element airfoil. A cell-vertex or vertex-based spatial discretization method and explicit multistage Runge-Kutta time stepping are used. The vertex-based method is found to give better results than the cell-vertex method. In the latter method a larger amount of artificial dissipation is required since different control volumes are used for the discretization of the viscous and convective fluxes. The slow convergence of the time stepping method makes a multigrid acceleration technique indispensable