Department of Energy Engineering, Sharif University of Technology, P.O. Box 11365-11155, Tehran, Iran
Department of Mechanical Engineering, Sharif University of Technology, P.O. Box 11365-11155, Tehran, Iran
Natural convection flow is considered in an annular enclosure that is filled with a fluid-saturated porous medium. The top and bottom horizontal walls are insulated while outer vertical wall is cooled with a constant temperature and a linear temperature gradient applied to inner vertical wall.Dimensionless equations are solved numerically using Finite Volume Method (FVM) on a collocated non-uniform, orthogonal grid. Darcy–Forchheimer model is used to simulate the momentum transfer in the porous medium. The effect of Rayleigh, Darcy, Prandtl, solid-fluid Nusselt, heat generation parameters and effective conductivity ratio of phases on the streamlines and isotherms are presented, as well as on the rate of heat transfer from the inner and outer vertical wall of the enclosure. It is concluded that at low values of effective conductivity ratio of phases, only the heat generation parameter has significant effect on the temperature field of the solid phase and the heat transfer from inner and outer vertical walls. An analytical solution is obtained for this case and compared with numerical solution. The resultsshow good agreements together.