Numerical prediction of performance drop due to cavitation in a centrifugal pump

Abstract

In order to predict cavitation performance drop of the centrifugal pump, the RNG κ-ɛ turbulence model and the mass transport cavitation model are applied to simulate the cavitation flows in a centrifugal pump at different flow rates. The influence of condensation coefficient of the mass transport cavitation model on numerical simulation is analysed. According to the calculation result, the value of condensation coefficient is modified. The calculated variation of pump head and efficiency at different flow rate agrees well with the experimental data. The results demonstrate that the numerical model and method can accurately predict the cavitation flows in a centrifugal pump. The cavitation flow fields in the centrifugal pump are revealed. The results show that the cavity bubbles firstly appear in the blade suction side and then develop to the middle of blade-to-blade channel. When the cavitation bubbles increase and then block the normal flow in the impeller, the pump head gradually drops. The detailed evolutions of cavitation structure in the centrifugal pump impeller are presented to provide beneficial references to the centrifugal pump optimization design.