Heat-Transfer Coefficients in Agitated Vessels. Sensible Heat Models

1995 ◽  
Vol 34 (12) ◽  
pp. 4571-4576 ◽  
Author(s):  
Enio Kumpinsky
Keyword(s):  
Heat Transfer ◽  
Sensible Heat ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients

Diffusion Layer Theory for Turbulent Vapor Condensation With Noncondensable Gases

1993 ◽  
Vol 115 (4) ◽  
pp. 998-1003 ◽  
Author(s):  
P. F. Peterson ◽  
V. E. Schrock ◽  
T. Kageyama
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Mass Transfer ◽  
Vapor Condensation ◽  
Sensible Heat ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Noncondensable Gas ◽  
Noncondensable Gases ◽  
Vertical Tubes

In turbulent condensation with noncondensable gas, a thin noncondensable layer accumulates and generates a diffusional resistance to condensation and sensible heat transfer. By expressing the driving potential for mass transfer as a difference in saturation temperatures and using appropriate thermodynamic relationships, here an effective “condensation” thermal conductivity is derived. With this formulation, experimental results for vertical tubes and plates demonstrate that condensation obeys the heat and mass transfer analogy, when condensation and sensible heat transfer are considered simultaneously. The sum of the condensation and sensible heat transfer coefficients becomes infinite at small gas concentrations, and approaches the sensible heat transfer coefficient at large concentrations. The “condensation” thermal conductivity is easily applied to engineering analysis, and the theory further demonstrates that condensation on large vertical surfaces is independent of the surface height.

Latent and Sensible Heat-Transfer Rates in the Boiling of Binary Mixtures

1982 ◽  
Vol 104 (3) ◽  
pp. 474-478 ◽  
Author(s):  
J. R. Thome
Keyword(s):  
Heat Transfer ◽  
Heat Transport ◽  
Binary Mixtures ◽  
Boiling Heat Transfer ◽  
Constant Heat Flux ◽  
Absolute Pressure ◽  
Sensible Heat ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Boiling Heat Transfer Coefficient

Nucleate pool boiling bubble departure data were obtained for the liquid nitrogen-argon cryogenic binary mixture system at 1.3 atmospheres absolute pressure. The latent and sensible heat transport rates at individual boiling sites were calculated from the data to deduce their effect on the degradation in the boiling heat-transfer coefficient in binary mixtures. The latent heat-transfer rate is a result of the bubble evaporation mechanism and the sensible heat-transport rate is due to cyclic thermal boundary layer stripping by departing bubbles. The latent and sensible heat-transport rates at individual boiling sites were found to decrease to a minimum at the maximum vapor-liquid mole fraction difference for both constant heat flux and wall superheating conditions. The large decrease in binary boiling heat-transfer coefficients was thus partially explained by the retardation of these two mechanisms and should be included in any model for predicting boiling heat-transfer coefficients in binary and multicomponent mixtures.

The use of heat transfer coefficients in estimating sensible heat loss from the pig

1977 ◽  
Vol 25 (3) ◽  
pp. 271-279 ◽  
Author(s):  
L. E. Mount
Keyword(s):  
Heat Transfer ◽  
Body Weight ◽  
Heat Loss ◽  
Radiant Heat ◽  
Heat Losses ◽  
Sensible Heat ◽  
Transfer Coefficients ◽  
Wind Speeds ◽  
Heat Transfer Coefficients ◽  
Environmental Temperatures

SUMMARYHeat transfer coefficients are used to calculate convective and radiant heat losses from pigs of 4, 20 and 60 kg body weight at 20 and 30 °C environmental temperatures for different wind speeds. Comparisons with heat losses estimated from whole-animal calorimetry suggest that calculations with heat transfer coefficients can lead to useful approximate estimates of heat loss from the pig.

scholarly journals Laboratory Measurements of Heat Transfer and Drag Coefficients at Extremely High Wind Speeds

2018 ◽  
Vol 48 (4) ◽  
pp. 959-974 ◽  
Author(s):  
Satoru Komori ◽  
Koji Iwano ◽  
Naohisa Takagaki ◽  
Ryo Onishi ◽  
Ryoichi Kurose ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Tropical Cyclones ◽  
High Speed ◽  
Analytic Model ◽  
Sensible Heat ◽  
High Wind ◽  
Transfer Coefficients ◽  
Drag Coefficients ◽  
Wind Speeds ◽  
Heat Transfer Coefficients

AbstractHeat and momentum transfer across the wind-driven breaking air–water interface at extremely high wind speeds was experimentally investigated using a high-speed wind-wave tank. An original multi-heat-balance method was utilized to directly measure latent and sensible heat transfer coefficients. The results show that both heat transfer coefficients level off at low and normal wind speeds but increase sharply at extremely high wind speeds. The coefficients have a similar shape for wind speeds at a height of 10 m. Therefore, the wind speed dependence on the latent and sensible heat transfer coefficients can be represented by that of the enthalpy coefficient even in the extremely high-speed region. To show how significantly the drag and enthalpy coefficients affect the intensity of tropical cyclones, the coefficients were applied to Emanuel’s analytic model. The analytic model shows that the difference between the present laboratory and conventional correlations significantly affects the maximum storm intensity predictions, and the present laboratory enthalpy and drag coefficients have the remarkable effect on intensity promotion at extremely high wind speeds. In addition, the simulations of strong tropical cyclones using the Weather Research and Forecasting (WRF) Model with the present and conventional correlations are shown for reference in the appendix. The results obtained from the models suggest that it is of great importance to propose more reliable correlations, verified not only by laboratory but also by field experiments at extremely high wind speeds.

Sign in / Sign up

Export Citation Format

Share Document