Parameter investigation on Eulerian–Lagrangian model for cryogenic cavitation considering thermal effects of discrete bubbles

The transient and multiscale characteristics of cryogenic cavitation are dominated by the complex interplay between phase change and thermodynamic effects, posing significant challenges for accurate prediction. This work incorporates a discrete bubble model (DBM) considering the thermal effect of discrete microbubbles into the volume of fluid (VOF) method to develop an Eulerian-Lagrangian model for cryogenic cavitation. The modified Zwart-Gerber-Belamri (ZGB) cavitation model is employed to describe the phase change of liquid nitrogen at a macroscopic scale. For discrete microbubbles, a random nucleation method within the Lagrangian framework is employed to distribute bubble nuclei in low-pressure regions, followed by the simulation of bubble growth and collapse using a simplified Rayleigh-Plesset equation. By coupling between VOF and DBM, this approach captures both large-scale vapor cavities and discrete microbubbles, effectively accounting for their dynamics, mass transfer, and thermal effects. Particularly, the present work focuses on investigation of model parameters for growth and collapse of cryogenic bubble considering thermal effects. The results indicate that the periodic shedding frequency and the bubble collapse rate agree well with the experimental results when the growth and collapse coefficients for discrete bubbles are 0.01 and 0.0001 respectively. Considering the thermal effect of discrete bubbles, the detailed temperature field evolution induced by microbubbles can also be obtained. The model not only deepens the understanding of multiscale cryogenic cavitation characteristics, but also provides a foundation for the optimal design of high-performance cryogenic fluid machinery.