Phase transition properties of thin liquid films with various thickness on different wettability surfaces

Abstract

Thin liquid film phase transition is often used to solve high heat flux heat transfer problem due to the high heat transfer coefficient. Both the surface wettability and the liquid film thickness are key factors affecting the phase transition behaviors of thin liquid films, however, the microscopic mechanism of the coupling effect is still unclear. Molecular dynamics method was employed to study the phase transition properties of liquid films with three thicknesses on six types of surfaces with different wettabilities, including hydrophilic, weak-hydrophilic, hydrophobic, and three hydrophilic-hydrophobic hybrid wettabilities. Results showed that explosive boiling occurred only when the temperature of the explosive boiling region reached the triggering temperature. The thermal resistance R1 at the solid-liquid interface, the thermal resistance R2 of the thin liquid film above the explosive boiling region, and their magnitude relationship determined the temperature rise rate of the explosive boiling region, then the phase transition mode and the onset time of explosive boiling (TOB) were further affected. Moreover, for hybrid surfaces, bubbles were easier to be generated in the hydrophobic region. The phase transition mechanism of thin liquid film on surface with different wettabilities was given in detail