Magnetohydrodynamic CuO-water nanofluid flow in a porous semi annulus with constant heat flux is studied by means of Control Volume based Finite Element Method. Koo-Kleinstreuer-Li correlation and Darcy model are applied for nanofluid and porous media, respectively. Effective parameters are radius of inner cylinder, CuO-water volume fraction, Hartmann and Rayleigh numbers for porous medium. A formula for Nu is presented. Results revealed that heat transfer augmentation decreases with rise of buoyancy forces. Influence of adding nanoparticle augments with increase of Lorentz forces. Increasing Hartmann number leads to a reduction in temperature gradient. (C) 2016 Elsevier Ltd. All rights reserved.