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Dropwise condensation modeling suitable for superhydrophobic surfaces / Sunwoo Kim in Journal of heat transfer, Vol. 133 N° 8 (Août 2011) 

Public ISBD [article]  in Journal of heat transfer > Vol. 133 N° 8 (Août 2011) . - pp. [081502/1-8] Titre : Dropwise condensation modeling suitable for superhydrophobic surfaces Type de document : texte imprimé Auteurs : Sunwoo Kim, Auteur ; Kwang J. Kim, Auteur Année de publication : 2011 Article en page(s) : pp. [081502/1-8] Note générale : Physique Langues : Anglais (eng) Mots-clés : Dropwise  condensation  Contact  angle  Hydrophobicity  Surface  wettability  Drop  size  distribution Index. décimale : 536 Chaleur. Thermodynamique Résumé : A mathematical model is developed to represent and predict the dropwise condensation phenomenon on nonwetting surfaces having hydrophobic or superhydrophobic (contact angle greater than 150 deg) features. The model is established by synthesizing the heat transfer through a single droplet with the drop size distribution. The single droplet heat transfer is analyzed as a combination of the vapor-liquid interfacial resistance, the resistance due to the conduction through the drop itself, the resistance from the coating layer, and the resistance due to the curvature of the drop. A population balance model is adapted to develop a drop distribution function for the small drops that grow by direct condensation. Drop size distribution for large drops that grow mainly by coalescence is obtained from a well-known empirical equation. The evidence obtained suggests that both the single droplet heat transfer and drop distribution are significantly affected by the contact angle. More specifically, the model results indicate that a high drop-contact angle leads to enhancing condensation heat transfer. Intense hydrophobicity, which produces high contact angles, causes a reduction in the size of drops on the verge of falling due to gravity, thus allowing space for more small drops. The simulation results are compared with experimental data, which were previously reported. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO00013300 [...] [article] Dropwise condensation modeling suitable for superhydrophobic surfaces [texte imprimé] / Sunwoo Kim, Auteur ; Kwang J. Kim, Auteur . - 2011 . - pp. [081502/1-8]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 133 N° 8 (Août 2011) . - pp. [081502/1-8] Mots-clés : Dropwise  condensation  Contact  angle  Hydrophobicity  Surface  wettability  Drop  size  distribution Index. décimale : 536 Chaleur. Thermodynamique Résumé : A mathematical model is developed to represent and predict the dropwise condensation phenomenon on nonwetting surfaces having hydrophobic or superhydrophobic (contact angle greater than 150 deg) features. The model is established by synthesizing the heat transfer through a single droplet with the drop size distribution. The single droplet heat transfer is analyzed as a combination of the vapor-liquid interfacial resistance, the resistance due to the conduction through the drop itself, the resistance from the coating layer, and the resistance due to the curvature of the drop. A population balance model is adapted to develop a drop distribution function for the small drops that grow by direct condensation. Drop size distribution for large drops that grow mainly by coalescence is obtained from a well-known empirical equation. The evidence obtained suggests that both the single droplet heat transfer and drop distribution are significantly affected by the contact angle. More specifically, the model results indicate that a high drop-contact angle leads to enhancing condensation heat transfer. Intense hydrophobicity, which produces high contact angles, causes a reduction in the size of drops on the verge of falling due to gravity, thus allowing space for more small drops. The simulation results are compared with experimental data, which were previously reported. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO00013300 [...]