Abstract
Critical heat flux -CHF- on subcooled flow boiling under oscillatory flow, focusing on liquid velocity, amplitude and frequency of oscillations were investigated experimentally and analytically. 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. The critical heat flux for oscillatory flow was lower than that for steady flow. The decreasing of liquid velocity by oscillatory caused the CHF to decrease. The CHF under the oscillatory flow condition was examined analytically by using a liquid sub-layer model, a lumped-heat-capacity model in the heater and the combined (Hydraulics and Heat Conduction) model.
