Water droplet impact behaviour on cold hydrophobic surface*

Experimental study of a droplet impingement on a hydrophobic surface has been performed by visualizing the temporal variation. The NaCl solution was mainly used and, droplets were formed at a tip of flat needle by using electrostatic potential. The free falling droplet impacted on a cold hydrophobic metal surface, which was visualized by using a high-speed camera and LED light. After having impingement on the surface, the droplet has a process of rebound, recoil and splash. Depending on the size of the droplet, we observed that after a collision, the dynamic behaviour of the droplet, the size of the droplet spreading and splashing, which depends on the size of the volume.