scholarly journals Closure to “Discussion of ‘Measured Temperature Profiles Within the Superheated Boundary Layer Above a Horizontal Surface in Saturated Nucleate Pool Boiling of Water’” (1965, ASME J. Heat Transfer, 87, pp. 340–341)

1965 ◽  
Vol 87 (3) ◽  
pp. 341-341
Author(s):  
B. D. Marcus ◽  
D. Dropkin
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Pool Boiling ◽  
Horizontal Surface ◽  
Temperature Profiles ◽  
Measured Temperature ◽  
Nucleate Pool Boiling

Measured Temperature Profiles Within the Superheated Boundary Layer Above a Horizontal Surface in Saturated Nucleate Pool Boiling of Water

1965 ◽  
Vol 87 (3) ◽  
pp. 333-340 ◽  
Author(s):  
B. D. Marcus ◽  
D. Dropkin
Keyword(s):  
Boundary Layer ◽  
Temperature Distribution ◽  
Pool Boiling ◽  
Heating Surface ◽  
Heat Fluxes ◽  
Temperature Profiles ◽  
Measured Temperature ◽  
Nucleate Pool Boiling ◽  
Average Temperature ◽  
The Heat Transfer Coefficient

Temperature measurements were made within the superheated boundary layer above and adjacent to a horizontal heating surface in saturated, nucleate, pool boiling of water. A microthermocouple probe was used to measure the average temperature profiles and the temperature fluctuations within the boundary layer at heat fluxes from 1000 to 40,000 Btu/hr-sq ft. Correlations are presented for the “extrapolated” thickness of the boundary layer (δ) as well as the temperature distribution within it. It was found that the thickness (δ) could be expressed in terms of the heat-transfer coefficient as: δ = Chd. Also, the behavior of δ with system parameters was found to agree with that predicted by Han and Griffith [3] and Hsu [4] in their theories of nucleation from surface cavities. The temperature distribution in the boundary layer from the surface to 0.57δ was essentially linear and could be expressed: (T − Tb)/(Ts − Tb) = 1 − (y/δ). Above 0.57δ the temperature profile became an inverse power function of the height above the surface: (T − Tb)/(Ts − Tb) = D(y/δ)−a.

Photographic Study of Nucleate Pool Boiling on a Horizontal Surface

1965 ◽  
Vol 87 (1) ◽  
pp. 17-27 ◽  
Author(s):  
R. F. Gaertner
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Active Sites ◽  
Pool Boiling ◽  
Nucleate Boiling ◽  
Copper Surface ◽  
Horizontal Surface ◽  
Transfer Model ◽  
Nucleate Pool Boiling ◽  
Platinum Surface

A photographic study was made of saturated nucleate pool boiling at a pressure of one atmosphere. Over 1000 still photographs and 12 high-speed motion pictures were taken of water boiling from a 2-in-dia flat horizontal surface facing upward. Two surfaces were studied, a 2/0 polished platinum surface and a 4/0 polished copper surface. The platinum surface was studied in the heat flux range of 14,700 to 176,000 Btu/hr, sq ft, and the copper surface from the incipient boiling heat flux of 10,500 Btu/hr, sq ft to the maximum flux of 493,000 Btu/hr, sq ft. Data were obtained for the breakoff diameters of discrete bubbles, and for the populations of active sites at heat fluxes up to 58,600 Btu/hr, sq ft. At least three, and possibly four, heat-transfer regions were found to exist in nucleate boiling, depending upon the mode of vapor generation. The vapor structures on the surface progressed through a sequence of first discrete bubbles, then vapor columns and vapor mushrooms, and finally vapor patches, as the surface temperature was increased. These individual vapor structures, or combinations of them, determine the mechanism of heat transfer in the four nucleate boiling regions. It was concluded that any heat-transfer model or design equation which is based on the dynamics of individual bubbles, or on any other single mechanism, must be in serious error.

Nucleate Pool Boiling Heat Transfer in Microgravity

1998 ◽  
Vol 29 (1-3) ◽  
pp. 196-207
Author(s):  
Haruhiko Ohta ◽  
Koichi Inoue ◽  
Suguru Yoshida ◽  
Tomoji S. Morita
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Nucleate Pool Boiling ◽  
Pool Boiling Heat Transfer
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