抄録
When a small solid body is irradiated with ultrasonic waves in a liquid medium, a significant temperature rise occurs in the body. The main causes of this phenomenon may be classified into two types, one is due to ultrasonic absorption in the interior of the body, the other due to heat production in the liquid layer close to the surface irradiated by ultrasonic waves. The existence of surface heating was discovered and reported by one of the authors about twenty years ago, but many problems concerning the phenomena still remained unclarified The authors examined about these both experimentally and theoretically and were able to observe two types of heating separately. The characteristics of surface heating and absorption heating were revealed by fused quartz and polyethylene, respectively.
