Investigation of the Cavitation Phenomenon in Centrifugal Pumps over Different Operating Flow Rates

Abstract

Cavitation flow phenomena are closely linked to the design and functioning of centrifugal pumps. This phenomenon can arise in the stationary portions of the pumps or in the revolving runner-impeller. This research aimed to study cavitation behaviour in a centrifugal pump at different operating flow rates: 0.5 Q, Q, 1.5 Q, and 2 Q (Q: design flow rate). The cavity formation issue can be found using a computational model (ANSYS CFX R.16). To overcome the initial cavitation, the total pressure at the inflow border gradually decreases. The novelty of this work is to accurately predict the cavitation behaviour in a centrifugal pump at half time, one and a half times, and twice the designed flow rate. The calculated CFD findings indicate that high-velocity liquid is the source of bubble formation in a lower-pressure region. Cavitation initiates on the blade surface, where the leading edge and tip meet. As the NPSH decreases, the cavitation zones move from the leading edge to the trailing edge. The head-NPSH curve begins to drop as the cavity size reaches the optimum chord length of the blade.