Heat transfer model of dropwise condensation and experimental validation for surface with coating and groove at low pressure

2015 ◽  
Vol 52 (1) ◽  
pp. 113-126 ◽  
Author(s):  
C.-H. Lu ◽  
M. Beckmann ◽  
S. Unz ◽  
D. Gloess ◽  
P. Frach ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Validation ◽  
Low Pressure ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Dropwise Condensation

Droplet Departure Characteristics and Dropwise Condensation Heat Transfer at Low Steam Pressure

2016 ◽  
Vol 138 (7) ◽  
Author(s):  
Rongfu Wen ◽  
Zhong Lan ◽  
Benli Peng ◽  
Wei Xu ◽  
Xuehu Ma ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Atmospheric Pressure ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Steam Pressure ◽  
Low Pressure ◽  
Vertical Surface ◽  
Transfer Model ◽  
Dropwise Condensation ◽  
Enhance Heat Transfer

Dropwise condensation has received significant attention due to its great potential to enhance heat transfer by the rapid droplet removal. In this work, droplet departure characteristics on a vertical surface, especially the droplet departure retention at low steam pressure and its effect on the heat transfer performance are investigated experimentally. The energy dissipation increases during droplet movement due to the increased viscosity at low pressure. Droplet oscillation caused by excess kinetic energy weakens and the dynamic contact angle (CA) hysteresis becomes apparent, which is not beneficial to droplet departure. Condensed droplets grow larger and fall more slowly at low pressure compared to that at atmospheric pressure. The droplet moves smoothly downward once it grows to departure size at atmospheric pressure while the droplet exhibits an intermittent motion at low pressure. Based on the droplet departure characteristics, a unified heat transfer model for dropwise condensation is developed by introducing the pressure-dependent departure velocity. The modified model very well predicts heat transfer performances at various pressures and the nonlinearity of heat flux varying with surface subcooling is quantitatively explained. This work provides insights into the heat transfer mechanism of dropwise condensation and offers a new avenue to further enhance heat transfer at low steam pressure.

scholarly journals Global sensitivity analysis of a pure steam dropwise condensation heat transfer model

2021 ◽  
Vol 2116 (1) ◽  
pp. 012012
Author(s):  
Jakob Sablowski ◽  
Simon Unz ◽  
Michael Beckmann
Keyword(s):  
Heat Transfer ◽  
Sensitivity Analysis ◽  
High Sensitivity ◽  
Nucleation Site ◽  
Heat Transfer Model ◽  
Model Parameters ◽  
Transfer Model ◽  
Dropwise Condensation ◽  
Input Parameters ◽  
Pure Steam

Abstract Established heat transfer models for dropwise condensation (DWC) consider wetting behavior, surface structure and nucleation dynamics to calculate the heat flux. However, model results often deviate from experiments, in part due to uncertainties of the model input parameters. In this study, we apply quantitative sensitivity analysis to a pure steam DWC heat transfer model in order to attribute the variation of the model result to its input parameters. Four scenarios with different variations of the model parameters are discussed and sensitivity coefficients for each parameter are calculated. Our results show a high sensitivity of the model result towards the coating thickness, the contact angle and the nucleation site density, underlining the need to accurately determine these parameters in DWC experiments.

Experimental validation of a heat transfer model for concentrating photovoltaic system

2012 ◽  
Vol 33-34 ◽  
pp. 175-182 ◽  
Author(s):  
Natarajan Sendhil Kumar ◽  
Katz Matty ◽  
Ebner Rita ◽  
Weingaertner Simon ◽  
Aßländer Ortrun ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Validation ◽  
Heat Transfer Model ◽  
Photovoltaic System ◽  
Transfer Model

scholarly journals 3D heat transfer model of hybrid laser Nd:Yag-MAG welding of S355 steel and experimental validation

2011 ◽  
Vol 54 (7-8) ◽  
pp. 1313-1322 ◽  
Author(s):  
Emilie Le Guen ◽  
Muriel Carin ◽  
Rémy Fabbro ◽  
Frédéric Coste ◽  
Philippe Le Masson
Keyword(s):  
Heat Transfer ◽  
Experimental Validation ◽  
Heat Transfer Model ◽  
Mag Welding ◽  
Transfer Model
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