Free Convection Film Boiling Heat Transfer From a Rotating Surface

1992 ◽  
Vol 114 (3) ◽  
pp. 695-702 ◽  
Author(s):  
J. Orozco ◽  
H. Francisco
Keyword(s):  
Free Convection ◽  
Surface Flux ◽  
Film Boiling ◽  
Integral Approach ◽  
Vapor Film ◽  
Experimental Facility ◽  
Layer Model ◽  
Rotating Surface ◽  
Minimum Heat ◽  
Good Agreement

A boundary layer model of laminar, subcooled, free convection film boiling from a rotating sphere has been developed. The conservation equations for the vapor and liquid were simplified, transformed into ordinary differential equations using an integral approach, and solved numerically. The theoretical variation of vapor film thickness with heater temperature and the resulting boiling fluxes were investigated. An experimental facility was built for the purpose of verifying the validity of the theoretical model and good agreement was found between the model and the experimental data at low rpm. The instability of the vapor film near the minimum heat flux for a rotating surface flux was also investigated.

On the Minimum Film Boiling Conditions for Spherical Geometries

1980 ◽  
Vol 102 (2) ◽  
pp. 335-341 ◽  
Author(s):  
F. S. Gunnerson ◽  
A. W. Cronenberg
Keyword(s):  
Experimental Data ◽  
Heat Flux ◽  
Flat Plate ◽  
Analytical Method ◽  
Boiling Point ◽  
Film Boiling ◽  
Heater Surface ◽  
Wide Range ◽  
Minimum Heat ◽  
Good Agreement

An analytical method is presented for predicting the minimum heater temperature and the minimum heat flux at the onset of film boiling for spherical and flat plate heaters in saturated and subcooled liquids. Consideration is given to a variety of factors known to affect the minimum film boiling point, including transient liquid-heater contact, interfacial wettability, heater geometry, and liquid subcooling. The theoretical correlations developed are the first known predictions for spherical geometries. A comparison of theory with experimental data indicates good agreement for the minimum heat flux and the minimum film boiling temperature. Results indicate that the minimum conditions may span a wide range depending upon the thermophysical nature of the heater surface and the boiling liquid.

On the Prediction of the Minimum Pool Boiling Heat Flux

1980 ◽  
Vol 102 (3) ◽  
pp. 457-460 ◽  
Author(s):  
J. H. Lienhard ◽  
V. K. Dhir
Keyword(s):  
Heat Flux ◽  
Film Boiling ◽  
Vapor Film ◽  
Saturated Liquid ◽  
Flat Plates ◽  
Rate Of Increase ◽  
Constant Rate ◽  
Empirical Generalizations ◽  
Film Collapse ◽  
Minimum Heat

A criterion is offered for the collapse of film boiling in a saturated liquid at the minimum heat flux. The criterion says the vapor film collapse occurs when insufficient vapor is generated to sustain the growing wave after it reaches a constant rate of increase of amplitude. This criterion yields an accurate prediction for horizontal flat plates and cylinders. The prediction requires the use of empirical generalizations about the configuration of film boiling, which are also developed here.

scholarly journals Incipience of the intensive heat transfer regime at cooling high-temperature bodies in subcooled liquid

2021 ◽  
Vol 2057 (1) ◽  
pp. 012049
Author(s):  
P K Kanin ◽  
V V Yagov ◽  
A R Zabirov ◽  
M A Lexin
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Solid Wall ◽  
Longitudinal Velocity ◽  
Vertical Plane ◽  
Film Boiling ◽  
Vapor Film ◽  
Subcooled Liquid ◽  
Wall Superheat ◽  
Good Agreement

Abstract Cooling in film boiling is usually an unwanted process in many technologies due to low intensity of heat transfer. Thus, predicting the solid wall superheat at vapor film destabilization is useful to avoid this phenomenon. In the present paper, two new semi-empirical models for evaluation of the wall superheat at destabilization of vapor film around the metallic body cooled in saturated or in subcooled liquid are proposed. Both models with fitted empirical multipliers are in good agreement with an experimental dataset. To evaluate the contribution of the natural convection in the model for temperature head at cooling in subcooled liquid, a problem about the natural convection near the vapor film, occurring during film boiling along the vertical plane, is numerically solved by means of ANES20XE CFD-code. The computational results of longitudinal velocity are in good agreement with the theoretical velocity of natural convection used in the model.

The structure of the Cincinnati arch as determined by short period Rayleigh waves

1969 ◽  
Vol 59 (1) ◽  
pp. 399-407
Author(s):  
Robert B. Herrmann
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Layer Thickness ◽  
Rayleigh Waves ◽  
Layer Model ◽  
Depth Data ◽  
Short Period ◽  
Best Fitting ◽  
Good Agreement

Abstract The propagation of Rayleigh waves with periods of 0.4 to 2.0 seconds across the Cincinnati arch is investigated. The region of investigation includes southern Indiana and Ohio and northern Kentucky. The experimental data for all paths are fitted by a three-layer model of varying layer thickness but of fixed velocity in each layer. The resulting inferred structural picture is in good agreement with the known basement trends of the region. The velocities of the best fitting theoretical model agree well with velocity-depth data from a well in southern Indiana.

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