MEASUREMENT OF THE FLOW AROUND THE SUBMERGED VORTEX CAVITATION IN A PUMP INTAKE BY MEANS OF PIV

The flow structure of the vortex occurring in a pump suction intake sump has been investigated and the accuracy of CFD calculation predicting vortex cavitation evaluated experimentally by using particle image velocimetry to measure the flow around the vortex. The test apparatus consisting of the model suction intake and the pressure tank could control the mean inlet velocity, the circulation, and the pressure at the pump intake bell mouth. Vortices of various strengths were generated using this apparatus, and velocity fields around them were measured and compared — with respect to the velocity distribution, the circulation, and the core radius — with the corresponding fields obtained by CFD calculation. The results of those comparisons and the difference between the instantaneous and time-averaged velocity profiles are described and discussed.