Progress in Numerical Simulation of Turbulent Cavitating Flow in an Axial Waterjet Pump

Abstract

A progress made in numerical simulation of turbulent cavitating flow in an axial waterjet pump (ONR AxWJ-2) is presented. The computational approach is designed to resolve the interaction between the rotor and the stator both in time and in space comprising the full 360° sector of the pump, using a scalable finite-volume-based Navier-Stokes solver. Unsteady Reynold-Averaged Navier-Stokes (URANS) and a hybrid of URANS and Large Eddy Simulation (LES) are employed for turbulence modeling and also for directly capturing some of large-scale coherent structures in the flow. A continuum mixture approach based on phasic volume-fraction is adopted along with a finite-rate mass-transfer model. It is shown that both the major quantities of interest (QOI) of waterjet pumps and the salient features of the flow such as tip-leakage vortex (TLV) cavitation can be predicted with a commendable accuracy.