Examinations of Behavior of Liquid Irradiated with High-Intensity Aerial Ultrasonic Waves in a Long Pore

Abstract

We experimentally verified the method of using the radiation force of high-intensity aerial ultrasonic waves at a frequency of 20 kHz to remove a liquid that entered a long pore. It was found that, on the wall surface of a cavity formed in the pore after the liquid had been removed by irradiating with ultrasonic waves, a small number of residual liquid drops linearly accumulated at multiple positions along the internal circumference of the cavity wall. The positions irregularly changed as the removal progressed. It can be considered that this phenomenon was mainly caused by the acoustic radiation force produced by nonlinear aerial ultrasonic waves. To explain this phenomenon, we observed in detail the behavior of the liquid; in addition, we performed a simulation of the acoustic radiation force produced by nonlinear aerial ultrasonic waves in a long pore, and compared the results of the simulation with the observed behavior of the liquid.