Je. Leland et Lc. Chow, FORCED-CONVECTION BOILING FROM A NONFLUSH SIMULATED ELECTRONIC CHIP, Journal of thermophysics and heat transfer, 7(4), 1993, pp. 588-594
An experimental investigation has been undertaken to determine the eff
ect of heated surface height on forced convective boiling. An inert fl
uorocarbon, FC-72 (3M Industrial Chemical Products Division) is circul
ated through a vertical rectangular channel at velocities of 1-4 m/s a
nd subcoolings of 20 and 35-degrees-C. Results for five surface height
s, as measured relative to the flow channel wall, were obtained. These
were 0.127-mm recessed, 0.229-, 0.457-, and 0.635-mm protruded and fl
ush with the flow channel wall. A reduction in critical heat flux (CHF
) occurred at low velocities, while an increase occurred at higher vel
ocities for the protruded cases. A reduction of CHF occurred at all ve
locities for the recessed condition. Additional results in the velocit
y range of 5-7 m/s are presented for the flush condition. This data sh
ows that for velocities greater than 4 m/s, CHF becomes weakly depende
nt on the Weber number. Weak dependence on Weber number also implies a
direct proportionality to velocity and a weak dependence on heated le
ngth.