Samad Amini - Department of Chemistry, Yasouj University, Yasouj, Iran
Seyyed Mohammad Azami - Department of Chemistry, Yasouj University, Yasouj, Iran
Mahmood Moradi LM - Department of Physics, Yasouj University, Yasouj, Iran

In this study the heat transfer and fluid flow, water-Al2O3 nanofluid in microchannel, twodimensionalrectangular in volume fractions 2%, 4%, 6% and 8% nanoparticles and Reynoldsnumber from 10 to 50 using computational fluid dynamics (CFD) has been investigated. Thegoverning equations of continuity and momentum and thermal is solved by finite elementmethod and by applying initial and boundary conditions by using COMSOL Multiphysicssoftware. Simulation results have shown, the local Nusselt number water-Al2O3 nanofluid inReynolds number 6.9 and volume fractions 5% is a good agreement with experimental data [1].Increasing the Reynolds number leads to increases fluid velocity and increase the density ofstreamlines in the edge of the baffle and the creation of larger vortex flow that increases the heattransfer coefficient [2]. By increasing the number of baffles leads to the formation of therecirculation zone, which increased outlet temperatures due to better heat exchange fluid to thewalls of the microchannel .So that the output of fluid temperature in Reynolds number 40 in themicrochannel six baffle and in the microchannel one baffle is 322.35 K and 314.9 K,respectively. By increasing the height of baffle ,increase recirculation zone and then increase theheat transfer coefficient. But also the average output temperature is increased by increasingnano-particle volume fractions and viscosity affected on size zone. But the effect of the distancebetween the baffles, the average temperature of the microchannel output is low. Numericalmethod is useful to predict thermal performance microchannel system.

Microchannels, Computational Fluid Dynamics, Heat Transfer, Temperature, Nusselt