In the present study, forced convection of CuO–water nanofluid in a two dimensional parallel plate microchannel with and without micromixers has been investigated numerically. Two horizontal hot baffles were inserted between the adiabatic plates and three vertical baffles, which were attached on the plates, worked as micromixers in order to improve the cooling process. The effect of Reynolds number, Re = 10, 30, 60, 100, and 150 and nanoparticles volume fraction, from 0 to 4%, were examined on flow field and heat transfer. Different geometrical configurations for the arrangement of the hot baffles were tested. A FORTRAN code based on finite volume method was developed to solve the governing equations and SIMPLER algorithm was used for handling the pressure-velocity coupling. Simulations showed that the presence of micromixers and increasing the Reynolds number as well as nanoparticles volume fraction, increase the average Nusselt number. In order to achieve maximum heat transfer, best arrangements for the baffles were reported. It was also observed that the size of recirculation zones, which are created behind the micromixer baffles, increases with increasing Reynolds number and leads to better cooling
