Influence of the mass transfer model on the numerical prediction of the cavitating flow around a marine propeller

Cavitating flows, which can occur in a variety of practical applications, can be modelled using a wide range of methods. One strategy consists of using the RANS (Reynolds Averaged Navier Stokes) approach along with an additional transport equation for the liquid volume fraction, where mass transfer rate due to cavitation is modelled by a mass transfer model. In this study, we verify the influence of three widespread mass transfer models, mainly on the numerical predictions of the propeller performances. The models in question share the common feature of employing some empirical coefficients to tune the models of condensation and evaporation processes, which can influence the accuracy and stability of the numerical predictions. For this reason, and for a fair and congruent comparison, the empirical coefficients of the different mass transfer models are first equally well tuned using an optimization strategy. The numerical predictions of the propeller performances based on the three different well-tuned mass transfer models are very close to each other. Unfortunately, the numerical cavitation patterns are slightly overestimated compared to the experimental ones, and the thrust breakdown is not properly predicted either. Finally, we roughly verify that for the prediction of the model scale propulsive performances in the presence of the partial and tip vortex cavitation, the turbulence model, among those considered in this study, plays a minor role.