Numerical Simulation of the Cavitation Flow Inside the Jet Pump

Abstract

Jet pumps have the advantages in reliable operation, none of moving components and simple construction etc, which makes it applicable in a wide range of industry situations. The cavitation easily occurs within jet pumps and it turns to be a bottleneck for the jet pump design. In this paper, the cavitation flow inside the jet pump would be investigated by 2-D axisymmetric CFD simulations. Firstly, the single liquid phase flow in the jet pump would be simulated and the grid independence test would be carried out. The simulation results show that both the pressure ratio (h) and the efficiency (n) would reach to convergence values with 143,484 meshes, which would be adopted in the following simulations. By comparing with the experimental data of single phase flow in literatures, it was found that the Reynolds stress model offered better predictions. Then the cavitation flow in the jet pump was simulated. It could be found that the cavitation phenomenon trends to occur in the shear layer and the wall detached regions of the throat. At last, the influence of saturated vapor pressure model, the outlet pressure and the nozzle-to-throat clearance would be evaluated. It was found that different from the single phase flow, the optimal nozzle-to-throat clearance would vary with the operation conditions.