Authors : Chokri Debissi Hfaiedh , Abdelaziz Nasr , Jamel Orfi , Amine Belhadj Mohamed and Sassi Ben Nasrallah
Abstract: The present study focuses on a numerical investigation of steady conjugated heat and mass transfers by forced convection in an externally heated or insulated channel. One wall is partially wetted by an extremely thin water film, while the other is dry and impermeable. The partially humid plate is divided into 2.n equal regions, which are alternately humid and dry zones. The effect of the number of wetted zones and their positions on the flow, on the heat and mass transfers is analysed. The results are reported in terms of axial distribution of wall temperature, relative heat fluxes and evaporative rate for different wetted zone positions. It is noticed that the change of the wetted zone position has no significant effect on the moist air flow. However, the heat and mass transfers are extremely influenced by the presence of the wetted zones and their positions. As the condition of an insulated channel, the evaporative rate is more intense when the wetted zone is situated at the channel entrance. In case of the condition of a heated wall channel, the situation is generally inversed. It is also shown that there exists a critical value for the density heat flux from which the behaviour of the evaporative rate is reversed. Finally, it is noticed that the evaporation is intensified by increasing the number of humid zones.
Chokri Debissi Hfaiedh , Abdelaziz Nasr , Jamel Orfi , Amine Belhadj Mohamed and Sassi Ben Nasrallah , 2008. Numerical Analysis of the Evaporation of Water by Forced Convection into Humid Air in Partially Wetted Vertical Plates. Journal of Engineering and Applied Sciences, 3: 811-821.