Computing and Mathematical Sciences Colloquium

Cut cell methods are very popular for inviscid flow simulations since they handle extremely complicated geometry and are easily automated. However, cut-cell methods are rarely used for high-Reynolds number flows, since without body-fitted grids it is extremely inefficient to resolve the fine scales of a boundary layer. In this talk I will describe our basic mesh generator and flow solver for inviscid flows, and the extensions needed to compute viscous flow using the Spalart-Allmaras turbulence model. We have developed a subgrid-based wall model for use with cut cell grids that is very efficient and gives better results than the analytic wall functions that are typically used. Our model solves a two point boundary value problem where the endpoint values come from the underlying Cartesian grid, and it is coupled to the Cartesian grid in a fully conservative way. We will show two dimensional computational results on a variety of benchmark cases.