Maximal enhancement of nanoscale boiling heat transfer on superhydrophilic surfaces by improving solid-liquid interactions: Insights from molecular dynamics

Abstract

The dramatic development in electronics results in an increasing cooling challenge. Nucleate pool boiling, as an efficient phase-change heat transfer technology without external energy consumption, is highly promising for sustainable high-heat-flux dissipation. To facilitate the design of boiling surfaces, an explicit understanding of effects of further reinforcements in the solid-liquid interaction on nucleate boiling over superhydrophilic surfaces is urgently desired. Whereas, it is considerably difficult to implement the relevant study and elucidate the underlying mechanism by current experimental approaches. Here, utilizing molecular dynamics simulations, effects of solid-liquid interactions on nucleate boiling over superhydrophilic surfaces are quantitatively illustrated. Our results manifest that, even for superhydrophilic surfaces, the bubble nucleation, growth and critical-heat-flux in nanoscale sense can be still strikingly enhanced with the improvement of solid-liquid interaction. Attractively, an optimal interaction energy coefficient (α = 1.5) for achieving maximal boiling enhancement is obtained in this study. The enhanced mechanism is elaborated by the heat transfer efficiency at the solid-liquid interface and energy barrier for phase-change. Additionally, it is found that conducting separate energy analyses for different liquid layers near the substrate is vital to reveal microscopic mechanisms thoroughly. This study provides significant guidance towards surface design in state-of-the-art thermal management systems.