In water supply installations, noise pollution often occurs. As a basic component of a system, a flush valve may frequently be a source of noise and vibration, of which cavitation can be the problem, especially during valve closing or valve opening.
The aim of this paper is to show how a numerical industrial code can point out a cavitation problem even if this code doesn’t use a cavitation model. This approach shows a good agreement with one using a cavitation model. The numerically obtained contours of the volume fraction of water vapour show cavitation inception distribution behind the poppet of the valve.
Computational Fluid Dynamics (CFD) simulations of cavitating flow through water hydraulic industrial flush valve were performed using the Reynolds averaged Navier-Stokes (RANS) equations with a near-wall turbulence model. The flow was turbulent, incompressible and steady. The flush valve under study is a real one. The structure of this flush valve was simplified due to symmetry considerations. The model used is three dimensional. Flow field vizualization was numerically achieved.
The effects of inlet pressure as well as mesh size and mesh type on cavitation intensity (assessed by pressure intensity) in the flush valve were numerically investigated thanks to two commercial codes : Fluent 6.3 and Star CCM+ 3.04.009.