Enhancement of Condensation Heat Transfer on a Finned Tube Using an Electric Field (Experiment and Modeling Analysis on Enhancement of Heat Transfer Using a Bare Wire Electrode)

2001 ◽  
Vol 8 (2) ◽  
pp. 99-118 ◽  
Author(s):  
Ren Cai C. Chu ◽  
Shigefumi Nishio ◽  
Ichiro Tanasawa
Keyword(s):  
Heat Transfer ◽  
Electric Field ◽  
Field Experiment ◽  
Finned Tube ◽  
Condensation Heat Transfer ◽  
Wire Electrode ◽  
Enhancement Of Heat Transfer ◽  
Modeling Analysis

Enhancement of Condensation Heat Transfer on a Finned Tube Using an Electric Field

2001 ◽  
Vol 8 (4) ◽  
pp. 215-229 ◽  
Author(s):  
Ren Cai C. Chu ◽  
Shigefumi Nishio ◽  
Ichiro Tanasawa
Keyword(s):  
Heat Transfer ◽  
Electric Field ◽  
Finned Tube ◽  
Condensation Heat Transfer

Electrowetting-Based Coalescence of Droplets During Dropwise Condensation of Humid Air

2019 ◽  
Author(s):  
Enakshi Wikramanayake ◽  
Vaibhav Bahadur
Keyword(s):  
Heat Transfer ◽  
Electric Field ◽  
Electric Fields ◽  
Applied Electric Field ◽  
Growth Dynamics ◽  
Condensation Heat Transfer ◽  
Droplet Growth ◽  
Dropwise Condensation ◽  
Condensation Rate ◽  
Humid Air

Abstract Dropwise condensation yields higher heat transfer coefficients by avoiding the thermal resistance of the condensate film, seen during filmwise condensation. This work explores further enhancement of dropwise condensation heat transfer through the use of electrowetting to achieve faster droplet growth via coalescence of the condensed droplets. Electrowetting is a well understood microfluidic technique to actuate and control droplets. This work shows that AC electric fields can significantly enhance droplet growth dynamics. This enhancement is a result of coalescence triggered by various types of droplet motion (translation of droplets, oscillations of three phase line), which in turn depends on the frequency of the applied AC waveform. The applied electric field modifies droplet condensation patterns as well as the roll-off dynamics on the surface. Experiments are conducted to study early-stage droplet growth dynamics, as well as steady state condensation rates under the influence of electric fields. It is noted that this study deals with condensation of humid air, and not pure steam. Results show that increasing the voltage magnitude and frequency increases droplet growth rate and overall condensation rate. Overall, this study reports more than a 30 % enhancement in condensation rate resulting from the applied electric field, which highlights the potential of this concept for condensation heat transfer enhancement.

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