Video Competition Winner

The third UK Fluids Network photo and video competition has finished, and voting is now closed. The winning video is shown below.

Click here to see the winning photo.

Controlling vortex breakdown in swirling pipe flow
David Dennis University of Liverpool A vortex breakdown occurs as fluid flows from a rotating pipe into a stationary pipe at a constant rate. The decaying swirl creates an adverse pressure gradient on the pipe axis, which reverses the flow and forms a recirculation "bubble". The bubble's size is controlled by the speed of rotation.