Liquid adhesion to an ultrasonically vibrating end surface

Abstract

There exists a unique phenomenon of a large amount of liquid adhering to an ultrasonically vibrating end surface in the horizontal plane. The droplet assumes characteristic shapes that depend on the amplitude of vibration. In order to examine the mechanism of this phenomenon, the effects of the intrinsic surface tension of the adhering liquid and distribution of the intensity of the acoustic radiation pressure on the adhering droplet were investigated. Based on the experimental results, a dynamic balance model of the adhering droplet was constructed considering the balance of weight, surface tension, and acoustic radiation pressure. The calculated shape of the adhering droplet using this model is in good agreement with that observed. The mechanism that allows a large amount of a liquid to adhere to the horizontal end surface is discussed, focusing on the distribution of the acoustic radiation pressure in the droplet.