Abstract
Onset of nucleate boiling -ONB- and critical heat flux -CHF- on subcooled flow boiling under oscillatory flow and vibration conditions, focusing on liquid velocity, amplitude and frequency of oscillations were investigated experimentally. Experiments were conducted using a copper thin-film and subcooled water in a range of the liquid velocity from 0.27 to 4.07 m/s at 0.10MPa. The liquid subcooling was 20K. Frequency of oscillatory flow was 2, 4 and 6 Hz, respectively; amplitude of oscillatory flow was 25 and 50 % in a ratio of main flow rate, respectively. For the vibration condition, acceleration of vibrator was 1.3 and 4.2 m/s2, respectively. Temperature at ONB and critical heat flux for oscillatory flow were lower than those for steady flow. The decreasing of liquid velocity by oscillatory caused the ONB and the CHF to decrease. Critical heat flux for the vibration condition was higher than that for steady flow. The effect of liquid oscillatory flow and vibration of heater on CHF examined through the liquid velocity profiles under oscillatory flow and vibration conditions. New correlation was proposed by using the present experimental data.
