Fully Transient CFD Analysis of Waterjet Pumps

Abstract

This paper presents results of fully transient calculations of the flow-through waterjet pumps. The fully transient method is based on a moving mesh option to implement the rotation of the impeller. In this way, the time-dependent forces, acting on the impeller, can be determined. These forces can be divided into axial and radial forces, e.g. as a result of rotor-stator interaction. In waterjet applications, the non-uniform inflow velocity distribution creates additional steady transverse impeller force in the stationary frame (in the horizontal and vertical direction). CFD analyses are made of two Lips-Jets waterjet pumps equipped with 3 and 6 bladed impellers to investigate the rotor-stator interaction force for various flow rates. Calculations with a non-uniform inflow velocity distribution are made to determine the steady transverse forces. The strength of this steady force depends on the amplitude of the velocity variations and the flow rate through the pump.