Evaporation dynamics of different sizes sessile droplets on hydrophilic and hydrophobic heating surface under constant wall heat fluxes conditions

Abstract In this study, an experimental investigation has been carried out to study evaporation of sessile droplets with different volumes on a heating surface under constant heat flux conditions. In this experiment, two sessile droplets were placed on a hydrophilic and a hydrophobic heating surface side by side. The droplets size ranged from 2 μl to 5 μl, and heat flux ranged from 1272 W/m 2 to 7810 W/m 2 . A high-speed camera was used to record the changing shapes of two sessile droplets. Effects of droplet size on dimensionless contact angle, dimensionless contact diameter, dimensionless droplet height and dimensionless evaporation rate, are presented.