This numerical study presents results of steady three-dimensional natural convection in a cubic box filled with fluid saturated porous medium. The porous medium is uniformly heat generating. All six faces are subjected to isothermal condition. The Darcy flow model    has been employed. The governing equations are numerically solved using successive accelerated replacement scheme. The maximum temperature and its location have been determined for wide range of Rayleigh number  As Rayleigh number increases, the value of maximum temperature decreases and its position shifts upward along mid vertical axis. There is a significant effect of Rayleigh number on flow and temperature fields.

natural convection, porous medium, internal heat generation, numerical study.