In this paper, a 2-D numerical study and a sensitivity analysis of convective heat transfer in a channel are investigated using the Discrete Phase Model along with determination of the nanoparticles concentration distribution. Numerical simulations are carried out to investigate the effects of the three parameters, the Reynolds number (250 <= Re <= 650), nanoparticles volume fraction (0.01 <= Phi <= 0.05) and nanoparticles diameter (40 nm <= dp <= 100 nm) on the heat transfer performance and nanoparticles distribution. In addition, the effective parameters analysis is performed utilizing the Response Surface Methodology. The results indicated that increasing the Re number and Phi and decreasing of dp, enhances the mean total Nusselt number. Also, an enhancement in dp and Phi and reduction of Re number increases the homogeneity of the nano-fluid. In addition, it is found that the sensitivity of the mean total Nusselt number to Re number, Phi and dp parameters is more than the sensitivity of the nanoparticles concentration ratio to these parameters. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.