Vorticity boundary conditions and boundary vorticity generation for two- dimensional viscous incompressible flows (Q1110405)

We present boundary conditions appropriate for the vorticity formulation of the two-dimensional incompressible viscous Navier-Stokes equations. These boundary conditions are incorporated into a finite difference scheme and the resulting method is of the ``vorticity creation'' type; i.e., vorticity is generated at the boundary to ensure that the tangential velocity boundary condition is satisfied. The results of computations with this finite difference method are presented for flow past a circular cylinder. A difference scheme and computational results for a model problem, the Prandtl boundary layer equations describing flow over a semi-infinite flat plate are also presented.