A thermodynamic cavitation model-driven exploration of entropy generation in two-phase flow cavitation

Cavitation in high-temperature water systems causes significant energy losses and material damage, yet most cavitation models neglect the influence of thermodynamic effects during cavitation flow, leading to inaccurate predictions. This study addresses this gap by developing an enhanced Extensional Schnerr-Sauer (ESS) cavitation model that incorporates temperature-dependent effects through a minimum growth rate approach minṘi,Ṙt and coupled heat transfer mechanisms. Simulations on the cavitating flows around a NACA 0015 hydrofoil at angles of attack of 5° and 8°, with cavitation numbers of 1.50 and 1.61, across temperatures ranging from 298 K to 473 K, demonstrate the superiority of the model over conventional approaches. Results demonstrate that the ESS model predicts reduced cavitation volumes at elevated temperatures as expected, e.g., 3 % lower at 343 K and 5 % lower at 473 K compared to the standard Schnerr-Sauer (SS) model while minimizing energy losses through optimized entropy production. The modified model also reveals significant reduction in temperature gradients up to 23 % in cavitation zones due to enhanced latent heat absorption from the surrounding liquid, which suppresses vaporization rates, lower local vapor pressure induced by thermodynamic coupling, reducing the driving force for phase change and optimized cavity dynamics from the minimum growth rate criterion. Additionally, the study identified a significant interplay between vortex structures and cavitation development, emphasizing the roles of rotational and shear effects in cavity growth, detachment, and shedding in dynamic cavitating flows. These findings provide critical insights for designing more efficient high-temperature fluid machinery systems, demonstrating that proper accounting of thermodynamic effects can significantly improve performance predictions and reduce cavitation damage.