超音波による膜沸騰伝熱の促進 : 第1報,白金細線を用いての一般的挙動に関する実験

抄録

The effect of ultrasonic wave application on film boiling heat transfer is investigated. A series of heat-transfer experiments are carried out using a fine heater made of a 0.20-mm-dia. horizontal platinum wire, which is immersed in saturated ethyl alcohol and exposed to a 28 kHz ultrasonic wave. The heat-transfer coefficient increases with the increase of power supplied to a ferrite-type vibrator and it is doubled for the maximum in this experimental condition. The minimum heat-flux point is also improved. At a lower degree of superheat than the MHF line, nucleate boiling and film boiling coexist separately along the platinum wire with a high reproducibility. The film boiling configuration is also observed through photograpty. Under a high intensity of ultrasonic wave, many tiny bubbled begin to generate and the shapes of large bubble becomes rather irregular.