Coupled Effects of Wall Vibration and Surface Wettability on Nanoscale Liquid Film Boiling: A Molecular Dynamics...

Nanoscale liquid film boiling is a key heat transfer mechanism in high-heat-flux thermal management, but the coupled effects of wall vibration and surface wettability remain unclear. In this study, molecular dynamics simulations were performed to investigate water film boiling on platinum surfaces under different wettability conditions, vibration amplitudes, and vibration frequencies. The results show that surface wettability strongly regulates the balance between early nucleation and later heat transfer deterioration. Under wall vibration, the neutral-wettability case (β = 0.02) shows the most favorable overall behavior, with bubble nucleation occurring at 0.35 ns, 46.2% earlier than that for β = 0.013, while the Leidenfrost onset is delayed to 1.65 ns, 153.8% later than that for β = 0.1. For vibration amplitude, increasing the amplitude from 0.5 to 2 Å advances bubble nucleation by 70.8%, whereas further increasing the amplitude to 3-4 Å accelerates Leidenfrost onset by 51.5-75.8%. For vibration frequency, compared with the non-vibrating case, nucleation is advanced by 36.4%, 54.5%, and 81.8% at 100, 150, and 200 GHz, respectively. These results indicate that moderate vibration enhances interfacial energy exchange, whereas excessive vibration promotes premature vapor-layer formation and heat transfer deterioration.