x u

Abstract. The paper is concerned with the problem of free convection boundary layer over horizontal permeable surfaces in porous media with internal heat generation. Our contribution extends two of our previous studies on the same subject, which were dealing with impermeable vertical and horizontal surfaces and with permeable vertical surfaces respectively. The present solutions are valid for a fluid-porous medium with an exponential decay heat generation term. Taking the wall temperature distribution proportional to xλ and denoting by γ the mass transfer rate through the wall, the velocity and temperature profiles and the local Nusselt number are obtained for various values of λ and γ. Key words: boundary layer, convection, porous media, internal heat generation. 1. Analysis For the problem of free convection boundary layer over horizontal permeable surfaces in porous media with internal heat generation, the basic equations are the continuity equation, Darcy’s law and energy equation (1