Water droplet freezing on cold surfaces with distinct wetabilities

This paper investigates the total freezing time of droplets on surfaces with various wettabilities with horizontal and inclined orientations. A two-dimensional Volume of Fluid (VOF) method was applied to capture the liquid-air interface, and an automatic localized grid treatment technique was applied to increase the accuracy, especially near the impact and spreading areas. The Kistler and Shikhumurzaev dynamic contact angle models were implemented to impose the dynamic contact angles on different surfaces. An enthalpy-porosity technique was used to predict the phase change of droplets after impact with the surface. The results of the nondimensional droplet diameter ratios and total freezing times for both dynamic contact angle models have been presented and verified with experimental data. The effects of both wetting properties and the surface inclination on the freezing time have been analyzed. The results indicate that a lower surface temperature, a decrease in static contact angle and a higher inclination will result in more rapid freezing of droplets.