Numerical investigation of turbulent cavitating flow in an axial flow pump using a new transport-based model

Abstract

With the aim to enhance the capability of predicting cavitating flows for conventional cavitation models, a developed alternative numerical model was proposed based on an alternative truncated Rayleigh-Plesset equation and the homogeneous flow assumption. Particularly, the effect of vortex on mass transfer was accounted in the formulation of the proposed model. Turbulent cavitating flows under various flow rates in an axial flow pump with a specific speed ns = 692 were computed and compared by the proposed and the Schnerr-Sauer models, for which the experimental results were also presented for guidance. The results show that the cavitation performance predicted by the proposed model agrees better with the experiments than that by the Schnerr-Sauer model. The effect of vortex on mass transfer results in different patterns of the tip leakage vortex (TLV) cavitation near the tip leakage. Further, the solution of the proposed model reveals the corner vortex cavitation, shear layer cavitation and TLV cavita-tion could be integrated into a cloud vapor at critical cavitation number, and the cloud cavity sheds and collapses periodically near trailing edge of blade.