Recent Advances in CFD Simulations of Multiphase Flow Processes with Phase Change

Abstract

Phase change is a phenomenon that has been extensively utilized in chemical engineering, energy, electronics, vehicle, and space exploration. From both the science and engineering perspectives, gaining a profound understanding of the intricacies of multiphase flow processes accompanied by heat and mass transfer due to phase change is of fundamental importance. Indeed, the computational fluid dynamics (CFD) has been increasingly applied as an effective tool to give an in-depth and efficient analysis of the phase change processes, thereby enhancing our understanding and capacity to control and optimize the phase change effects in these processes. This paper seeks to provide a comprehensive review of the utilization of CFD methodologies in the simulations of phase change flows across various applications, including temperature management, drying, separation and purification, and others. First, the CFD models at various scales that are developed to elucidate the phase change processes are summarized. Second, the noteworthy advances in the recent CFD simulation work on various phase change processes are presented, respectively. Finally, the challenges and potential prospects to facilitate the application of the phase change flow are discussed. The current review aims to offer insightful guidance for the CFD modeling of phase change processes in numerous engineering application scenarios.

Mixing Due to Natural Convection in a Hydrothermal Reactor: A CFD Study

“…However, the Lee model was also not developed for a system with such a wide temperature variation, and presumably more advanced models , should be employed for a better match of the pressure. Given that the current results are reasonably close to the experimental values and that an exact match of the gas phase pressure is usually superfluous when simulating hydrothermal reactors, the standard form of the Lee model may be a good choice due to its robustness and limited computational burden . Some more comments on these observations are provided in the Supporting Information.…”

“…Previous research has shown that this model has some shortcomings, such as the neglect of the superheat needed to activate nucleation sites in the liquid, and more complex alternatives have been proposed . Nonetheless, the model is widely employed in the literature, and here it was selected as a reasonable compromise. For the coefficients γ l and γ v , the Fluent guide recommends tuning their values to match the experimental results, while Sun et al .…”

Fundamentals and Applications of Surface Wetting

“…Here, the previously mentioned dynamic contact angle models play a vital role. , Another exciting research area that needs intense future research is the modeling and incorporation of contact angle hysteresis . Followed by this, numerical modeling of phase change heat transfer processes is an ongoing research topic . Lastly, using machine learning to identify flow fields and flow structures in complex multiphase flow scenarios is also gaining popularity. , …”

Research Needs and Pathways to Advance Hydrothermal Carbonization Technology

“…However, HTC also involves other phenomena that are usually not relevant for other systems. One of these is evaporation and other phase transfers [4]: their inclusion is mandatory to assess the gas pressure and yield, but such models clearly complicate the setup [69]. Furthermore, the evaporation models commonly applied in the literature were not originally designed for systems with such substantial temperature variations.…”