Unsteady natural convection heat transfer within a porous square enclosure with insulated rectangular obstacles on the top and bottom walls

Numerical investigation of unsteady natural convection heat transfer in a porous square enclosure with insulated rectangular obstacles on horizontal walls has been performed. The fluid inside the enclosure considered is air, two horizontal walls are adiabatic while the left wall is hot and the right wall is maintained at cold temperature. The governing equations are written based on Darcy’s law and then solved numerically using finite volume method with FLUENT software. The Boussinesq approximation is employed for the fluid properties and density change is related to temperature change which in this way the temperature field is coupled to the flow field. The second order upwind scheme is used to discretize the convective and diffusive terms and SIMPLE solution algorithm is utilized to couple the pressure and velocity. The results show that obstacle height change and it’s number lead to more reduction of average Nusselt number than displacement of obstacle. .