The evaporation of a saturated porous layer inside an inclined airflow channel

Abstract

This study investigates the enhancement in the heat and mass transfer of liquid film evaporation obtained by introducing a liquid-saturated porous layer within an inclined flow channel. The liquid and air streams are modeled as two coupled laminar boundary layers incorporating non-Darcian models of the inertia and boundary effects and the numerical solution is obtained by means of a fully implicit finite difference method. The effects of the porosity ( ε), porous layer thickness ( δ), inclined angle ( φ), ambient relative humidity ( ϕ) and Lewis number ( Le) on the average heat and mass transfer performance are thoroughly examined. It is found that the porous layer enhances the heat and mass transfer performance. Specifically, the numerical results indicate that the average Nusselt number ( Nu) and the Sherwood number ( Sh) both increase with increasing φ, with decreasing ε and δ .The increase in ϕ results in the decreasing in Nu and increasing in Sh. Additionally, the influence of the porosity ( ε) on the heat and mass transfer performance becomes more significant as the thickness of the inclined angle ( φ) decreases.