Comparison of Various Turbulence Models Applied to a Twisted Hydrofoil

In the paper, various turbulence models are compared and different modifications employed to investigate more in deep to what extent the RANS are applicable to simulate the unsteady cavitating flow around a twisted foil. The predicted vapor shedding frequency and lift force coefficient are compared with the experimental data. Moreover, the dynamics behavior induced by the cavitation is discussed in detail. The results show that frequency predicted by density correction based model (DCM) SST is much closer to the experimental data, but the model fails to predict the second shedding vapor. In general, DCM RNG shows a better prediction ability. Firstly, a vapor cloud is sheared toward downstream due to the effect of main flow and re-entrant flow. After that, the second shedding vapor catches up with the first one and becomes the main vapor. The oscillation of the lift coefficient changes consistently with the vapor fluctuations and when a second vapor shedding is highlighted, a second peak value occurs in the time history of lift coefficient.