抄録
We found that micro-bubbles were generated from the orifice located at the oscillating end of hollow ultrasonic horn. Consecutive images obtained using a high-speed video camera and high-resolution snapshots using CCD camera with a microscope reveals that the generation of microbubble causes by the primary break-up of the gas-liquid interface near the horn end and the secondary break-up of released bubbles. We also investigated the dissolved oxygen concentration in water with bubbles generated by this generator. These results show microbubbles under 50 μm in diameter are generated only when an oscillation displacement of the horn end is over 49.6 μm (peak-to-peak).
