Nanoparticle migration effects on fully developed forced convection of TiO2-water nanofluid in a parallel plate microchannel

This study considers the forced convection of laminar TiO2-water nanofluid flow in a parallel plate microchannel. The small length scale associated with microchannels dictates the use of slip condition at the fluid-solid interface. The modified Buongiorno model was employed for the nanofluid to fully account for the effects of non-uniform viscosity and thermal conductivity. The partial differential equations associated with conservation laws were reduced to two-point ordinary boundary value differential equations before being numerically solved. Considering Brownian motion and thermophoresis, the effects of nanoparticle transport on concentration, velocity, and temperature profiles were analyzed for three different values of wall heat flux. To assess the efficiency of adding nanoparticles, the ratios of the pressure drop and the heat transfer coefficient of the nanofluid to that of the base fluid were studied in detail. From analyzing different heat flux ratios, one-sided heating was found to be most efficient at enhancing the heat transfer rate in the microchannel. Additionally, in the presence of the slip velocity, the increase in the value of the heat transfer coefficient for the nanofluid was smaller than that for the base fluid. (C) 2015 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.