Molecular Dynamics Study on Water Condensation on Periodic Triangular Serrated Surfaces With Varying Wettability

Abstract

Abstract. Condensation plays a fundamental role in both theoretical research and practical applications, with its efficiency significantly influenced by surface characteristics. Using molecular dynamics (MD) simulations, this study investigates water condensation on periodic triangular serrated surfaces with varying wettability (hydrophilic, neutral, and hydrophobic). By analyzing condensation patterns, cluster coalescence, condensation rates, temperature distributions, and heat flux variations, we systematically explore the synergistic effects of surface serration and wettability on condensation dynamics and underlying mechanisms. The results reveal that wettability dominates the condensation modes: hydrophilic surfaces promote filmwise condensation, hydrophobic surfaces induce dropwise condensation, and neutral surfaces yield columnar liquid clusters. On serrated surfaces, cluster coalescence time increases with decreasing wettability. Specifically, it decreases monotonically with increasing groove number on hydrophilic and neutral surfaces, whereas an opposite trend is observed on hydrophobic surfaces. Both condensation rate and heat flux decline monotonically with decreasing wettability, and the strong correlation between condensation rate and heat flux confirms energy dissipation via latent heat release. Temperature distribution reveals preferential nucleation at groove bottoms. This study indicates the synergistic effect of surface serration and wettability on nanoscale condensation, providing theoretical insights for the design of high-efficiency heat transfer surfaces in micro/nano-engineering.