An Experimental Study of Tip Vortex Cavitation Inception in an Axial Flow Pump

The interaction of the blade tip with the casing boundary layer and the leakage flow may lead to a kind of cavitation namely tip vortex cavitation. In this study, the onset of tip vortex cavitation was experimentally investigated in an axial flow pump. For a constant speed and a fixed angle of attack and by changing the flow rate, the pump head, input power, output power and efficiency were calculated and the pump characteristic curves were obtained. The cavitation phenomenon was observed with a camera and a stroboscope. Finally, the critical flow region, which tip vortex cavitation might have occurred, was identified. The results show that just by adjusting the flow rate, out of the specified region, the possibility of occurring tip vortex cavitation, decreases to a great extent.

Authors:

• Mohammad Taghi Shervani Tabar
• Zahra Poursharifi

Keywords:

• Axial flow pump
• Gap cavitation
• Leakage vortex
• Tip vortex cavitation.

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