Vortex-mediated bouncing drops on an oscillating liquid surface
Hong-Yu Chu1*
1Department of Physics, National Chung Cheng University, ChiaYi, Taiwan
* presenting author:曲宏宇, email:phyhyc@ccu.edu.tw
We have investigated the behavior of bouncing drops on a liquid surface by using particle image velocimetry analysis. A drop on an oscillating liquid surface is observed to not coalesce with the liquid and to travel along the surface if the oscillation is strong enough. A streaming vortex pair, induced by the alternatively distorted liquid surface, appears below a bouncing drop. The time-averaged flow fields of the vortices are measured. Three stable distances of the drop-drop interaction are found in our quasi-one-dimensional setup, and characterized by the Faraday wavelength. The interactions of the vortex-mediated bouncing drops are deduced from the streamlines in the liquid bulk. We further show that the three bouncing drops are connected as coupled oscillators and a three-dimensional vortex ring is induced by a bouncing drop in a square cell.

Keywords: bouncing drop, acoustic streaming phenomena, vortex ring