A Kelvin–Clapeyron Adsorption Model for Spreading on a Heated Plate

Abstract

A new adsorption model for the spreading dynamics of completely wetting fluids on a heated solid substrate that emphasizes interfacial phenomena is developed and evaluated. The model is based on the premise that both interfacial intermolecular forces and temperature affect the vapor pressure in change-of-phase heat transfer and (therefore) the spreading velocity. Classical change-of-phase kinetics, and interfacial concepts like the Clapeyron, Kelvin, and the augmented Young–Laplace equations are used to evaluate the effects of stress (change in apparent dynamic contact angle), temperature, and superheat on the rewetting velocity. Explicit equations are obtained for the velocity, heat flux, and superheat in the contact line region as a function of the initial plate temperature. Comparisons with experimental data for substrate superheats below a critical value demonstrate that the resulting interfacial model of evaporation/condensation in the contact line region can describe the effect of the saturation temperature and superheat on the rewetting velocity.