Removal of Liquid in a Long Pore Opened at Both Ends Using High-Intensity Aerial Ultrasonic Waves

We experimentally verified a method by which a liquid that has entered a long pore with open ends can be removed from the pore by using the acoustic radiation force produced by high-intensity aerial ultrasonic waves at a frequency of 20 kHz. The intensity of the ultrasonic waves was about 6 to 10 kPa. By using this method, it was confirmed that a liquid in pores of 1.5 to 5.0 mm diameter and 3 to 20 mm length could be instantaneously removed from the pores. This method, which did not use any air flow at a high pressure, has the significant advantage that it does not produce any strong air flow around the pore. We consider the intensity of the ultrasonic waves required to remove the liquid, the time required to remove the liquid, and the quantity of liquid removed, all of which were determined by varying the diameter and length of the pore. (C) 2010 The Japan Society of Applied Physics