Application of WA-Algebraic Transition model in unsteady cavitation flow around a hydrofoil

A new WA-Algebraic Transition (WA-AT) model is used to investigate unsteady cavitation flow over a NACA 0009 hydrofoil. The new WA-AT turbulent model is combined with Zwart-Gerber-Belamri (ZGB) cavitation model to verify the feasibility and superiority of the WA-AT turbulent model in multiphase flow, especially in predicting cavitation, to help better understand the relationship between cavitation and vorticity. The components of the vorticity transport equation are quantified examined and discussed. The result shows that the WA-AT turbulence model can accurately predict the periodic processes of cavitation, the macroscopic characteristics and shedding frequency of cavitation can be simulated well. The cause of the unstable shedding of flake-like cavitation has been determined to be the re-entrant jet. The emergence of cavitation affects the local flow field velocity and significantly changes the distribution of local vorticity. The variation of vorticity depends largely on the shape of the cavity, and cavitation is an important factor in the generation of vorticity.