Numerical comparative study of heat transfer enhancement using three kinds of nanofluids
Authors: Abdelkrim Bouaffane
Volume 11, Issue 1, Paper No. 110104
Abstract
This numerical research is done on the hydrodynamic and thermal characteristics of laminar forced convection of different nanofluids inside horizontal tube. The tube wall is subjected to a constant heat flux condition. Al2O3-water, Cu-water, and SiO2-water are the three considered nanofluids examined in this study. The mathematical model of the present problem is based on the single phase approach, the governing equations are solved iteratively using the finite volume method. For nanoparticle volume fractions ϕ ranging from 0 to 6% and for two values of Reynolds numbers Re=1000 and 2000, Nusselt number, pressure losses (or pumping power), average friction factor and Performance evaluation criterion (PEC) are shown and discussed. The results demonstrate that the increase of ϕ enhances significantly the average Nusselt number particularly for Cu-water and Al2O3-water. When nanoparticles are added to pure water, the pumping power is negatively impacted because the augmentation of ϕ leads to increase the pressure drop. The highest pressure drop is occurred for Cu-water followed by Al2O3-water and SiO2-water. The comparison between the studied fluids indicates that the PEC values of Cu-water and Al2O3-water are greater than the unity, because they show a significant improvement in the rate of heat transfer with acceptable pressure losses. In the other hand, the PEC values related to SiO2-water are close to the unity due to the slight increase in average Nusselt number. Therefore, SiO2-water is ineffective for enhancing the convection heat transfer.
Keywords: Heat transfer enhancement; Nanofluid; Pressure drop; Pumping power; Friction factor.
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