A Vortex Sheet Method Applied to Unsteady Flow Separation from Sharp Edges

Abstract

A computational method is presented which describes the unsteady two-dimensional vortex generation and convection in stationary geometries with sharp edges. A second-order panel method is used to describe the motion of the two-dimensional vortex sheet, while the generation of vorticity at the sharp edges is enforced through a Kutta condition. In order to easily satisfy the normal-velocity boundary condition on the stationary walls, the flow domain is transformed to a half-plane ( x > 0) by a Schwarz-Christoffel conformal mapping. In the computational plane the solid walls are situated on the vertical coordinate axis so that image vorticity can be utilized to satisfy the boundary condition in a simple way. The method is applied to describe the separating impulsively started flow past a sharp-edged wedge and the flow in a channel with a deep cavity. These applications show that the method is able to describe vortex shedding in complex geometries in an accurate way.