Heat Transfer Through Thin Films: Approximate Analysis and Determination of Effective Heat Transfer Coefficient

1983 ◽  
Vol 105 (3) ◽  
pp. 673-674 ◽  
Author(s):  
L. E. Bobisud
Keyword(s):  
Heat Transfer ◽  
Thin Films ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Approximate Analysis ◽  
Effective Heat ◽  
Effective Heat Transfer Coefficient

scholarly journals Determination of effective heat transfer coefficient for water spray cooling of steel

2020 ◽  
Vol 50 ◽  
pp. 488-491
Author(s):  
Sampo Uusikallio ◽  
Sami Koskenniska ◽  
Joonas Ilmola ◽  
Jussi Paavola ◽  
Aarne Pohjonen ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Spray Cooling ◽  
Water Spray ◽  
Effective Heat ◽  
Effective Heat Transfer Coefficient ◽  
Water Spray Cooling

scholarly journals Experimental determination of the heat transfer coefficient during evaporation and boiling of thin liquid film

2018 ◽  
Vol 194 ◽  
pp. 01022
Author(s):  
Anastasia Islamova
Keyword(s):  
Heat Transfer ◽  
Thin Films ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Thin Liquid Film ◽  
Distilled Water ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
The Heat Transfer Coefficient

Thin films evaporation of distilled water, ethanol and HFE-7100 liquid was experimentally studied. The dependences of heat transfer coefficients in time were determined. It has been established that with a decrease in the layer thickness of distilled water and ethanol, the heat transfer coefficient increases. For the HFE liquid, the nature of the change is different: as the time increases, the heat transfer coefficient decreases.

Analysis of Laminar Heat Transfer on Super-Hydrophobic Surface With Slip Velocity

2009 ◽  
Author(s):  
Wei Sun ◽  
Yuhong Zhou ◽  
Xinxin Fan ◽  
Tianqing Liu
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Thermal Resistance ◽  
Transfer Coefficient ◽  
Slip Velocity ◽  
Structural Parameters ◽  
Hydrophobic Surface ◽  
Trapped Air ◽  
Effective Heat ◽  
Effective Heat Transfer Coefficient

It is still in suspense for the effects of slip velocity and structural parameters on the heat transfer on a super-hydrophobic surface. It is thus necessary to study it in both theory and experiments. In this paper, the convective heat transfer with constant heat flux condition inside a circular microchannel was investigated. The velocity and temperature profiles when slip velocity exists were derived firstly, and then the heat transfer coefficient and Nusselt number were obtained. Furthermore, an effective conduction model for the super-hydrophobic surface with different structural parameters was proposed and the thermal resistance of the surface with trapped air was calculated. Finally, the effective heat transfer coefficient of super-hydrophobic surface was found with the integration of heat transfer coefficient and surface thermal resistance. The calculation results show that 1) the slip of fluid on a super-hydrophobic surface makes the temperature profile inside the channel more uniform, and the heat transfer coefficient or Nusselt number increased, 1.8 times higher maximally under constant heat flux condition; 2) the thermal resistance of super-hydrophobic surface increases with trapped air volume; 3) the effective heat transfer coefficient on super-hydrophobic surface declines seriously with trapped air volume, especially with the trapped air area; 4) there exists a critical thickness for the trapped air on a super-hydrophobic surface with given surface structural parameters, under which the effective heat transfer coefficient is not less than that on normal surfaces without slip. Therefore, it is necessary to consider the structural parameters of super-hydrophobic surfaces, such as rib height and distance between ribs, so that the heat transfer on the super-hydrophobic surface will not be impacted by the trapped air.

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