Numerical analysis of unsteady cavitating flow in an axial inducer

Abstract

This article presents a numerical simulation of an unsteady cavitating flow. First, the analysis was carried out for a two-dimensional (2D) venturi-type geometry, and then for a 2D blade cascade simulating an axial inducer. The main purpose of this work is to explore the local cavitation instabilities, such as alternate blade cavitation and rotating blade cavitation, which can appear in axial inducers. The numerical simulation was performed using a commercial code based on a cell-centred finite-volume method. The cavitation model used for calculations assumes a thermal equilibrium between phases. It is based on the classical conservation equations of the vapour phase and the mixture phase, with mass transfer owing to the cavitation appearing as a source and a sink term in the vapour mass fraction equation. The mass transfer rate is derived from a simplified Rayleigh—Plesset model for bubble dynamics.