Turbulence model comparison for ventilated cavitation around a hydrofoil

Ventilated cavitation involves complex multiphase flow, phase change, and turbulence, posing challenges for accurate prediction and control. This paper investigates the performance of three turbulence models—Large Eddy Simulation (LES), Detached Eddy Simulation (DES), and Shear Stress Transport (SST)—in predicting the unsteady characteristics and entropy generation mechanisms in ventilated cavitation around a hydrofoil. A comparative analysis with experiments reveals each model's strengths and limitations in capturing cavitation and turbulence at various scales. The results demonstrate that the LES model excels in resolving small-scale turbulent structures, cavitation formation and shedding, as well as reverse flow and vortex dynamics, making it highly suitable for detailed analysis of complex cavitation phenomena. The DES model shows robustness in predicting large-scale flow features but exhibits delays when handling bubble motion near the hydrofoil's trailing edge. The SST model achieves a balance between computational accuracy and efficiency in predicting flow separation and vortex structures, making it ideal for trend analysis in engineering applications. By analyzing boundary vorticity flux lines, Q-criterion, and Omega methods, the study confirms the LES model's superior capability in capturing intricate vortex structures in high-turbulence regions, while also revealing the dynamic evolution of entropy generation during cavitation. Overall, the LES model proves to be the most effective for precise simulation of ventilated cavitation phenomena, while the DES and SST models are better suited for large-scale flow analysis and practical engineering applications, respectively. This research provides theoretical and technical support for the prediction and control of complex ventilated cavitation flows.