Assessment and Tuning of CFD Cavitation Model Parameters using Advanced Optimization Techniques

Cavitating flows which can occur in a variety of practical cases, can be modelled with a wide range of methods. One strategy consists of using the RANS (Reynolds Averaged Navier Stokes) equations and an additional transport equation for the liquid volume fraction, where mass transfer rate due to cavitation is modelled by a mass transfer model. Several mass transfer models are available in literature, but at least, the most popular employ some empirical coefficients to guide the condensation and evaporation processes. Moreover it seems that, to achieve accurate results, the empirical values of the models have to be properly tuned with respect to the solver and to the different cavitating regimes. For these reasons in this work we present a preliminary optimization strategy to properly tune and validate different mass transfer models. The optimization strategy is applied to the three popular mass transfer models, and the preliminary results for the cavitating flow around the Naca66(mod) hydrofoil are presented. The overall results suggest that the optimization strategy is stable, accurate and could be applied to additional mass transfer models and other cavitating flow phenomena.