Hydrodynamic analysis of nanofluid's convective heat transfer in channels with extended surfaces

Abstract

The effects of nanoparticles (NPs) on heat transfer in extended surface channels have been analyzed using a two-component (TC) model. The results show that unlike the single-component model, the TC model leads to more accurate predictions of the system's heat transfer performance as a result of the direct influence of the NPs' distribution on the hydrodynamics. It is found that the average Nusselt number varies non-monotonically with the block's heights, and the trend is explained by the interplay between heat transfer mechanisms and the hydrodynamics. A similar non-monotonic trend observed in the case of the friction factor has been explained by the variations of the concentration- and temperature-dependent viscosity of the nanofluids. A guideline for an optimum design based on the combination of the variation of average Nusselt number and friction factor with respect to the geometrical parameters has also been presented.