Experimental Study of Heat and Mass Transfer for Liquid Film Evaporation along a Vertical Plate Covered With a Porous Layer

Document Type : Special Issue Manuscripts

Authors

1 Laboroitoire d’Energétique et des transferts thermique et massique, Faculté des sciences de Tunis, Université Tunis El Manar, Tunisie

2 Université de Lille Nord de France, F-59000 Lille UVHC, LAMIH CNRS UMR 8201, F-59313 Valenciennes Cedex, France

Abstract

In this paper, we realized an Experimental study of heat and mass transfer for liquid evaporation along a vertical plate covered with a porous layer. To develop this study, an experimental dispositive was realized. To highlight the effect of the addition of a porous layer on the phenomenon of evaporation, we first study the case of the flow of a liquid film on an aluminium plate. Then we covered the same plate by a porous layer. We could measure the temperature along the plate and the evaporated flow using the test bed. From these measurements we note that temperatures are higher with the presence of the porous medium which affect positively on the evaporated flow. In addition, various dimensionless numbers were analyzed as the sensible and latent local Nusselt number, solving the energy equation by inverse method. We note that the latent Nusselt number is more important than the sensible Nusselt Number. Then the flow dissipated by evaporation is greater than that used by the film to increase its temperature. We also note that the calculated values of the latent and sensible Nusselt number are greater in the presence of the porous medium that proves that the addition of the porous layer improves heat and mass exchange.

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