Asymmetric vortexes induced traveling drop on an oscillatory liquid bath

摘要

The traveling and dancing behaviors of the bouncing drops on the oscillating liquid bath have been reported in several investigations. It was shown that the normal force during the impact of the drop on an inclined liquid surface is responsible for the traveling of a 0.8 mm-sized drop. Here, we report that a pair of vortexes can be induced by the repeated impact of a 2 mm-sized drop on an oscillatory liquid bath. The traveling of a large drop on the oscillatory liquid bath with an inclined bottom is found to be associated with the induced asymmetric vortex flow underneath the liquid surface. The effect of the vortex flow becomes significant for the size of a drop larger than 1.8 mm. Two-coupled drops with different sizes are found to be self-propelled on the oscillatory liquid bath with a flat bottom. The coupled drops propagate toward the direction of the small-sized drop. The distribution of the vortex flow is investigated by the particle image velocimetry (PIV) technique and the numerical simulation of the acoustic streaming model. PIV measurement and numerical simulation of the speed distribution of the vortex flows induced by the single bouncing drop and two-coupled drops show consistent results. It is suspected that the traveling of two-coupled drops is associated with the motion of the small drop and the liquid flow near the liquid surface. Published under license by AIP Publishing.