Numerical investigation of vortex breakdown

The breakdown of an isolated rotationally symmetrical vortex in an incompressible laminar parallel flow is investigated by numerical solution of the conversion equations. These equations are simplified via the boundary-layer approximation and discretized with a Crank-Nicholson scheme, and the resulting differential equations are solved with the Thomas algorithm. The flow field beyond the breakdown point is determined by numerical integration of the full Navier-Stokes equations, without assuming that the flow is steady. The results are presented in graphs and diagrams.