EFFECT OF AN INSERTED POROUS LAYER ON HEAT AND FLUID FLOW IN A VERTICAL CHANNEL WITH MIXED CONVECTION

Temperature and velocity fields in a vertical channel partially filled with porous medium under mixed convection heat transfer condition are obtained. The heat transfer equation and equation of motion for clear and porous layer regions are written and solved analytically. The non-dimensionalization of the governing equations yields two Grashof numbers as Gr(c) and Gr(d) for clear and porous sections where Gr(d) = Da.Gr(c). The dimensionless governing parameters for the problem are Gr(c) (or Gr(d)), Da, thermal conductivity ratio, and thickness of porous layer. The temperature and velocity profiles for different values of Gr(c), Da, thermal conductivity ratio, and thickness of porous layer are plotted and their changes with the governing parameters are discussed. Moreover, the variation of pressure drop with the governing parameters is investigated. The decrease of porous layer thickness or thermal conductivity ratio increases the possibility of the downward flows. Thermal conductivity ratio plays important role on pressure drop, particularly for the channels with high values of Gr(c)/Re.