Modelling of the interaction between a falling n-heptane droplet and hot solid surface

The resulting numerical model was validated through the experimental data of Chandra and Avedisian (Chandra, S., Avedisian, C.T., 1991. Proc. R. Soc. Lond., Ser. A 432, 13-41). Although some discrepancies were found between the numerical results and experimental data, the model was found to be capable of reproducing the reduced droplet spreading rate as the temperature of the surface is increased away from the saturation temperature. The decrease in rate of surface wetting results from the combined effects of surface tension, viscous forces and evaporation at the liquid-solid-vapour contact line. Further, the effects of increased pressure at the solid-liquid interface resulting from the rapid evaporation of the liquid, which in some cases can be quite severe such that the liquid gets lifted-off from the surface, were also captured, in good agreement with experimental observations. Finally, the effects of the solid temperature on the evaporation and heat transfer rates of the droplets were presented and analysed.