Euler-Lagrange study of cavitating turbulent flow around a hydrofoil

This study presented a multi-scale Eulerian-Lagrangian approach to simulate cavitating turbulent flow around a Clark-Y hydrofoil to study the bubble dynamics. A large eddy simulation was coupled with the volume of fluid method to capture the large vapor volumes in an Eulerian analysis. Micro-scale Lagrangian bubbles were then tracked by solving compressible the Rayleigh-Plesset equation and a bubble motion equation. A Gaussian kernel function was used to model the interactions between the flow field and the vapor bubbles in a coupled two-way algorithm. The predictions give satisfactory agreement with experimental data for the bubble size oscillations, bubble motion, and cavity shedding characteristics. Further investigations analyzed the influence of various parameters on the transformation between the Euler and Lagrange models. The numerical results provide detailed information about the influence of the cavitating turbulent flow on the bubble behavior, especially how the reentrant jet significantly affects the bubble generation and motion. The calculations also capture the bubble size oscillations caused by the surrounding liquid pressure variations and how these generate very high local pressures near the surface. The results show that the pressure wave released as a bubble is compressed reaches 10(7) Pa, which may cause cavitation erosion of the hydrofoil surface. This research provides a promising method to better investigate the bubble motion characteristics in macroscopic flows and demonstrates that the cavitation erosion caused by bubble size oscillations is significant and deserves attention.