Analysis of special phenomena of droplet impact on horizontal liquid film at low velocity

The outcomes of spreading, jetting, partial rebound and complete rebound when droplet impact on the horizontal liquid film at low velocity observed by high speed camera were analyzed, and the characteristic parameters of spreading and complete rebound were quantitatively analyzed by pixel analysis method. With the increase of We (rho v(2)D/sigma), different droplet impact outcomes were observed, such as complete rebound, partial rebound, jetting, and spreading. Daughter droplets appear when droplet merges into the liquid film after rebounding several times, which are larger when the droplet move upward, and smaller on the contrary. When droplet rebounds, the coefficient of deformation increases with the increasing of We. For fixed We, rebound outcome is favored at smaller Oh. (C) 2019 Elsevier Ltd. All rights reserved.