Isolated Vortex
 

I'm trying to generate a vortex to valuate the interaction with a profile placed downstream. The simulation is 2D. I've used a vortex generator with success (a profile with non zero angle of attack placed upstream) but I want to generate the vortex isolated. I've tried to initialize the velocity with field function to give the tangential velocity profile of Rankine but I can't let the vortex move with flux. Does anybody have an idea?
Thank U.