Numerical analysis of nucleation effects on cloud cavitation using multiscale Euler–Lagrange model

This study develops a hybrid multiscale Euler–Lagrange model to investigate the unsteady characteristics of cloud cavitation around a hydrofoil under different water qualities. A homogeneous mixture model is implemented for macroscopic cavity simulations, tracking the vapor–liquid interfaces. In the Lagrangian framework, the dynamics and motion of nuclei and bubbles are resolved. By incorporating more physically accurate conversion criteria to couple the two frameworks, the cavitation model is modified to ensure consistency with the assumption that cavitation inception arises from the expansion of nuclei. Numerical results, obtained under different size distributions of nuclei populations, align well with experimental data, validating the capability of the multiscale model to account for the effects of water quality. They also offer detailed insights into the influence of cavitation flows on microscale bubble behavior, particularly highlighting the significant role of reentry jets in bubble generation and motion. The results underscore the critical interplay between small-scale bubble dynamics and macroscopic cavitation flows. In addition, a statistical analysis of the size distribution of microbubbles reveals a distribution law consistent with experimental observations. This study provides a robust framework for investigating the comprehensive effects of water quality on cloud cavitation flows, offering a promising avenue for future research in this domain.