Fully Developed Forced Convection in a Parallel Plate Channel with a Centered Porous Layer

Abstract

In this study, fully developed heat and fluid flow in a parallel plate channel partially filled with porous layer is analyzed both analytically and numerically. The porous layer is located at the center of the channel and uniform heat flux is applied at the walls. The heat and fluid flow equations for clear fluid and porous regions are separately solved. Continues shear stress and heat flux conditions at the interface are used to determine the interface velocity and temperature. The velocity and temperature profiles in the channel for different values of Darcy number, thermal conductivity ratio, and porous layer thickness are plotted and discussed. The values of Nusselt number and friction factor of a fully clear fluid channel (Nu cl = 4.12 and fRe cl = 24) are used to define heat transfer increment ratio $$({\varepsilon _{\rm th} =Nu_{\rm p}/Nu_{\rm cl})}$$ and pressure drop increment ratio $$({\varepsilon_{\rm p} =fRe_{\rm p}/fRe_{\rm cl} )}$$ and observe the effects of an inserted porous layer on the increase of heat transfer and pressure drop. The heat transfer and pressure drop increment ratios are used to define an overall performance $$({\varepsilon = \varepsilon_{\rm th}/\varepsilon_{\rm p})}$$ to evaluate overall benefits of an inserted porous layer in a parallel plate channel. The obtained results showed that for a partially porous filled channel, the value of $${\varepsilon}$$ is highly influenced from Darcy number, but it is not affected from thermal conductivity ratio (k r) when k r > 2. For a fully porous material filled channel, the value of $${\varepsilon}$$ is considerably affected from thermal conductivity ratio as the porous medium is in contact with the channel walls.