Transient cavitating vortical flows around a hydrofoil using k-ω partially averaged Navier–Stokes model

Abstract

For accurate simulations of wall-bounded turbulent cavitating flows, the present paper proposed a partially averaged Navier–Stokes (PANS) method derived from the [Formula: see text]-[Formula: see text] turbulence model. Transient cavitating vortical flows around a NACA66 hydrofoil were simulated by using the [Formula: see text]-[Formula: see text] PANS model with various filter parameters ([Formula: see text] and [Formula: see text], while [Formula: see text]) and a mass transfer cavitation model based on the Rayleigh–Plesset equation. Compared with the available experimental data, the [Formula: see text]-[Formula: see text] PANS model with [Formula: see text] can accurately reproduce the cavitation evolution with more complicated structures due to the reduction in the predicted eddy viscosity. Further analyses, using the vorticity transport equation, indicate that the transition of cavitation structure from two dimension to three dimension is associated with strong vortex–cavitation interaction, where vortex stretching and dilation may play a major role. Therefore, the [Formula: see text]-[Formula: see text] PANS model with the filter parameter of [Formula: see text] is an effective method to numerically predict the transient cavitating vortical flows around hydrofoils. The results obtained in this paper are helpful to provide a physical insight into the mechanisms of cavitation shedding dynamics.