Simulation of the control of vortex breakdown in a closed cylinder using a small rotating disk

Abstract

The enhancement or suppression of vortex breakdown in a closed cylinder caused by a small rotating disk embedded in the nonrotating endwall is simulated in this study. This paper shows that corotation or counter-rotation of the control disk with respect to the driving lid is able to promote or suppress the “bubble-type” vortex breakdown. This is achieved using only a small fraction of the power required to drive the main lid. The simulations show that the vortex breakdown induced or suppressed by flow control displays similar characteristics near the breakdown region as produced by varying the flow Reynolds number. These include near-axis swirl, centerline axial velocity, and centerline pressure. The influence of the size of the control disk is also quantified.