Amplitude fixed with strength of background flow increasing

 

Animation of periodic vortices in a stagnation point flow showing how the form of the vortices varies as the strength of the background stagnation point flow increases. The left image shows the flow when viewed along the axis parallel to the direction of the diverging flow in the background stagnation point flow. The middle image shows the perturbation vorticity, and the right image shows the perturbation stream function. In this sequence the amplitude of the vortices is fixed so that the maximum value of the perturbation stream function is 80.