Abstract
The objective of the present study is to clarify macroscopic behavior of microbubble (MB) and acrylic particles in tap water under ultrasonic waves. Ultrasonic waves (in a traveling-wave field) at frequencies of 485 kHz and 3.493 MHz were irradiated on a microbubble-water mixture or an acrylic particles-water mixture in a vertical closed cylinder from the bottom with a disk transducer and ultrasonic waves at a frequencies of 96.3 kHz from the side wall in a rectangular vessel. The following results were obtained; (a) Macroscopic behavior of MB was affected by a directivity function while an effect of the function on behavior of acrylic particles was small. (b) Most MB were transported along radial lines from the center of the disk transducer at the frequency of 3.493 MHz, however, a few MB were transported in different directions. (c) Magnitudes of MB velocity were greater than those of acrylic particles. (e) The frequency became higher, MB was transported in the region of smaller deviation angle, i.e., near the irradiation axis.
