C202 STREAMING AND HEAT TRANSFER BY AN ULTRASONIC VIBRATION IN A WATER VESSEL(Heat transfer in complex system-2)

概要

論文の詳細を見る
The purpose of this report is to clarify the influence of streaming induced by an ultrasonic vibration on heat transfer through experimental investigation. For this purpose, the flow patterns in a water vessel by ultrasonic vibration are investigated experimentally. In tap water, vortex streaming of cavitation bubbles around the pressure node of a standing wave occurred because of the large number of cavitation bubbles generated by the ultrasonic vibration. Acoustic streaming of the Rayleigh type caused by cavitation bubble streaming is also induced in tap water. In a glycerin aqueous solution of 30%, Eckart streaming, which flowed upward from the vibrator, occurred due to the dissipation of ultrasonic energy caused by viscosity. The velocity of the acoustic streaming generated in the water vessel by 27.8 kHz vibration is 1 to 6 mm/s. The cavitation bubble streaming in tap water is completely independent of normal Rayleigh or Eckart streaming. This bubble streaming is considerably faster than previous streaming. As a result, by this streaming, the heat transfer coefficient is increased.
一般社団法人日本機械学会の論文
2000-10-01