Multiscale hybrid surface structure modifications for enhanced pool boiling heat transfer: State-of-the-art review

With substantial heat dissipation capacity and high energy efficiency, pool boiling represents a promising thermal management solution for high-power-density computing technologies. To address the increasing demand for improved heat dissipation, pool boiling heat transfer must be enhanced to attain a lower initial boiling temperature, increased heat transfer coefficient, and improved critical heat flux. Modification of surface structures is effective to achieve these enhancements, and recent studies have focused on multiscale hybrid surface structure modifications for synergistic effects. Compared with single-scale surface structure modifications, multiscale hybrid strategies are more complex in terms of enhancement mechanisms, influencing factors, and numerical modeling. However, timely reviews that explore and summarize these achievements are still lacking. To bridge this gap, this study presents a state-of-the-art review on multiscale hybrid surface structure modifications aimed at enhancing pool boiling heat transfers. First, This research introduces three typical scaled surface structure modifications, including macroscale, microscale, and nanoscale strategies. Subsequently, their hybrid use, enhancement mechanisms, and major influencing factors are systematically explored, reviewed, and summarized. Specifically, this research focus on macro/micro hybrid structures, micro/micro hybrid structures, micro/nano hybrid structures, and nano-amphiphilic structures. For each hybrid structure, different formats and combinations are presented and analyzed. Furthermore, the associated numerical modeling techniques are summarized and comparatively analyzed. Lastly, the major findings are outlined, and recommendations for future studies are highlighted. This review can serve as a timely contribution to advancing our understanding of multiscale hybrid surface structure modifications for enhanced pool boiling and provide guidance for advanced surface structure modification techniques.