A modified method considering vortex effect for modelling unsteady cavitating flows

The objective of this study is to propose a modified method for the cavitation model and turbulence model, accounting for the influence of vortex motion on unsteady cavitating flows. A function of the ratio of strain rate tensor and rotation rate tensor is introduced into the Zwart cavitation model and the shear stress transfer (SST) gamma-Re-theta t turbulence model respectively. The modified method is applied to simulate the unsteady cloud cavitating flow around Clark-Y hydrofoil and evaluated by the experimental data. The results show that the modified model can better capture the unsteady process of the cloud cavity, especially the fully developed attached cavity and the large-scale cloud shedding behaviors. These benefit from the increase of turbulent dissipation rate per unit energy and the evaporation rate of the modified method. In addition, the lift coefficient fluctuation in time and the time-averaged u-velocity profiles predicted by the modified model are better agreement with the experimental results.