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Measurement and modeling of condensation heat transfer in non-circular microchannels / Akhil Agarwal in International journal of refrigeration, Vol. 33 N° 6 (Septembre 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 6 (Septembre 2010) . - pp. 1169-1179 Titre : Measurement and modeling of condensation heat transfer in non-circular microchannels Titre original : Transfert de chaleur lors de la condensation à l'intérieur des micro-canaux non circulaires: mesures et modélisation Type de document : texte imprimé Auteurs : Akhil Agarwal, Auteur ; Todd M. Bandhauer, Auteur ; Srinivas Garimella, Auteur Année de publication : 2010 Article en page(s) : pp. 1169-1179 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Condensation  Microchannel  Heat  transfer  Model  Measurement  Non-circular Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Heat transfer coefficients in six non-circular horizontal microchannels (0.424 < Dh < 0.839 mm) of different shapes during condensation of refrigerant R134a over the mass flux range 150 < G < 750 kg m−2 s−1 were measured in this study. The channels included barrel-shaped, N-shaped, rectangular, square, and triangular extruded tubes, and a channel with a W-shaped corrugated insert that yielded triangular microchannels. The thermal amplification technique developed and reported in earlier work by the authors is used to measure the heat transfer coefficients across the vapor-liquid dome in small increments of vapor quality. Results from previous work by the authors on condensation flow mechanisms in microchannel geometries were used to interpret the results based on the applicable flow regimes. The effect of tube shape was also considered in deciding the applicable flow regime. A modified version of the annular-flow-based heat transfer model proposed recently by the authors for circular microchannels, with the required shear stress being calculated from a non-circular microchannel pressure drop model also reported earlier was found to best correlate the present data for square, rectangular and barrel-shaped microchannels. For the other microchannel shapes with sharp acute-angle corners, a mist-flow-based model from the literature on larger tubes was found to suffice for the prediction of the heat transfer data. These models predict the data significantly better than the other available correlations in the literature. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000149 [article] Measurement and modeling of condensation heat transfer in non-circular microchannels = Transfert de chaleur lors de la condensation à l'intérieur des micro-canaux non circulaires: mesures et modélisation [texte imprimé] / Akhil Agarwal, Auteur ; Todd M. Bandhauer, Auteur ; Srinivas Garimella, Auteur . - 2010 . - pp. 1169-1179. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 6 (Septembre 2010) . - pp. 1169-1179 Mots-clés : Condensation  Microchannel  Heat  transfer  Model  Measurement  Non-circular Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Heat transfer coefficients in six non-circular horizontal microchannels (0.424 < Dh < 0.839 mm) of different shapes during condensation of refrigerant R134a over the mass flux range 150 < G < 750 kg m−2 s−1 were measured in this study. The channels included barrel-shaped, N-shaped, rectangular, square, and triangular extruded tubes, and a channel with a W-shaped corrugated insert that yielded triangular microchannels. The thermal amplification technique developed and reported in earlier work by the authors is used to measure the heat transfer coefficients across the vapor-liquid dome in small increments of vapor quality. Results from previous work by the authors on condensation flow mechanisms in microchannel geometries were used to interpret the results based on the applicable flow regimes. The effect of tube shape was also considered in deciding the applicable flow regime. A modified version of the annular-flow-based heat transfer model proposed recently by the authors for circular microchannels, with the required shear stress being calculated from a non-circular microchannel pressure drop model also reported earlier was found to best correlate the present data for square, rectangular and barrel-shaped microchannels. For the other microchannel shapes with sharp acute-angle corners, a mist-flow-based model from the literature on larger tubes was found to suffice for the prediction of the heat transfer data. These models predict the data significantly better than the other available correlations in the literature. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000149