CFD Simulation of Pressure, Temperature and Rotational Speed Influence on the Cavitation in Centrifugal Pump Impeller

Abstract

The impeller is a critical rotating part of a centrifugal pump where the energy transfer to the fluid takes place. The complex nature of the fluid flow inside the impeller can give rise to cavitation which is highly undesirable. Design and operating conditions in the impeller influence the extent of cavitation. The effect of the outlet pressure, temperature and rotational speed of the impeller was studied using ANSYS CFX Computation Fluid Dynamics (CFD) software. The impeller geometry was meshed with high-quality hexahedral meshes and the y + values around the blade surface are less than 2. The k - omega turbulence model was used along with the ZGB model of cavitation. The effects of the variable parameters on the cavitation volume and the head developed were extensively studied. The numerical trends are similar to those presented in the literature. By carefully controlling the outlet pressure, the effects of increased temperature can be mitigated. Thus, it is possible to operate a centrifugal pump at higher working fluid temperatures by operating the pressure above 275 kPa.