Freezing behaviors of impacting water droplets on cold inclined surfaces

Freezing of impacting water droplets on cold inclined surfaces is ubiquitous in nature and many engineering applications. Most of previous studies are limited to the regime where the interaction between the solidification and drop-scale fluid dynamics are weak. In this work, we explore the freezing behaviors of water droplets upon impacting an inclined super-hydrophilic surface at a sufficiently low temperature, so as to improve the coupling effect between the solidification and drop-scale fluid dynamics. Different from an almost identical ice shape when the surface inclination angle alpha = 30 degrees, the ice at its leading edge becomes steeper with the subcooling degree Delta T when alpha = 45 degrees. Intriguingly, when alpha = 60 degrees, the interactions between rivulet dynamics and solidification result in the non-monotonic variations of the rivulet length with impact velocity. Besides, the increasing Delta T has negative (positive) effects on the rivulet length at the low (high) impact velocity regime. Furthermore, the slenderness of rivulet increases with.T, indicating the coupling degree between the solidification and rivulet dynamics.

Automated summary

This study explores the freezing behaviors of water droplets impacting super-hydrophilic surfaces at different inclinations and subcooling degrees. The results show that the ice shape and length of rivulets are influenced by the inclination angle and subcooling degree, indicating the coupling effect between the solidification and drop-scale fluid dynamics.