Numerical study of unsteady turbulent cavitating flows

Abstract

The simulation of cavitating flows is a challenging problem both in terms of modelling the physics and developing robust numerical methodologies. Such flows are characterized by important variations of the local Mach number, compressibility effects on turbulence and involve thermodynamic phase transition. To simulate these flows by applying homogeneous models and Reynolds averaged codes, the turbulence modelling plays a major role in the capture of unsteady behaviours. This paper presents a one-fluid compressible Reynolds-Averaged Navier-Stokes (RANS) solver with a simple equation of state (EOS) for the mixture. A special focus is devoted to the turbulence model influence. Unsteady numerical results are given for Venturi geometries and comparisons are made with experimental data.

A comparative study of cavitation models in a Venturi flow

“…For a correct simulation of the re-entrant jet, the Reboud eddy-viscosity limiter is added [29,30,31]. For comparisons with the OpenFOAM solver, the Menter k − ω SST model [32] is used, assuming the validity of the Bradshaw assumption [33] in a two-phase turbulent boundary layer.…”

Large eddy simulation of unsteady shedding behavior in cavitating flows with time-average validation

“…Among them, the Schnerr and Sauer model which is adopted in the present work has the simplest form and the only undetermined empirical constant is the bubble number density (Zhou et al, 2015). Despite of the extensive research efforts (Coutier-Delgosha et al, 2003;Saito et al, 2007;Yang et al, 2011;Goncalves, 2011;Ji et al, 2013;Huang et al, 2013;Goncalves, 2014;Goncalves and Charriere, 2014;Stanley et al, 2014) have been devoted to investigate the unsteady shedding and thermodynamic effects in cavitating flows, capturing the turbulent flow and its coupling effect with the cavitation remains as a challenging but crucial task in the modeling framework. The Reynolds Average Navier-Stokes (RANS) equation is widely adopted for simplicity, however, it is well known that the timeaverage technique has limitation in characterizing the transient or periodic behavior of unsteady cavitating flows (Chen and Lu, 2008;Lakshmipathy and Girimaji, 2010;Decaix and Goncalves, 2013;Huang et al, 2013;Ji et al, 2015).…”

Numerical Study of Unsteady Cavitating Flows around a Hydrofoil

“…Whereas the current Reynolds average NavierStokes (RANS) equation approach (Khlifi and Lili 2011) has been broadly used to model turbulent flows in manufacturing, the RANS models with eddy viscosity turbulence models have limited ability to simulate unsteady cavitating turbulent flows and need some modifications (Chen and Lu, 2008;Coutier-Delgosha et al, 2003;Decaix and Goncalves, 2013;Goncalves, 2011;Huang et al, 2013). Furthermore there have been attempts to predict the unsteady cavitating flow using LES (Aghaee-shalmani and Hakimzadeh, 2015).…”