Convective flow and heat transfer in an alumina/water nanofluid enclosure having two centered adherent porous blocks under the effect of moving upper wall have been analyzed numerically. The control parameters are the Richardson number (0.01 ≤ Ri ≤ 10), dimensionless porous blocks size (0.1 ≤ δ ≤ 0.4) and concentration of solid nanoparticles (0 ≤ ϕ ≤ 0.04). The calculated results have shown the growth of the heat transfer rate with nanoparticles concentration for forced convection regime (Ri < 1) and the heat transfer rate reduction for mixed and natural convection regimes (Ri ≥ 1) for the medium size of the porous blocks, while the average Nusselt number increases with the Richardson number for high size of porous blocks.