Structure of the Stagnation Point Flow in the Presence of Cross-Stream Vorticity in the External Flow

Abstract

The structure of the forward stagnation point flow past a circular cylinder in the presence of weak steady cross-stream vorticity in the external flow in the form of a Görtler-type disturbance to the basic flow is considered. It is shown that the stagnation point flow can support certain preferred modes of vorticity in the external flow, leading to a substructure of counter-rotating streamwise eddies in the boundary layer. The magnitude of the streamwise vorticity in the boundary layer is of the same order or smaller in the flow Reynolds number as that in the external flow.