Aluminum Oxide Nanofluid Energy Transfer

Nanofluid is a new class of heat transfer fluids engineered by dispersing metallic or non-metallic nanoparticles with a typical size of less than ۱۰۰ nm in the conventional heat transfer fluids.This article aims to investigate the overall and convection heat transfer coefficient and Nusselt number of Al۲O۳-water nanofluid flowing in a horizontal double pipe heat exchanger under turbulent flow () conditions. Al۲O۳ nanoparticles with diameter of ۲۰ nm dispersed in Deionized water with volume concentrations of  vol. are used as the test fluid. The results show that the overall and convection heat transfer coefficient and Nusselt number of nanofluid were approximately ۱۵% -۲۱% greater than that of pure fluid. Additionally, the heat transfer coefficient and Nusselt number increase with an increase in flow rate,Reynolds number, nanoparticle concentration and nanofluid temperature. Finally, the new correlations were proposed for predicting the Nusselt number of the nanofluids, especially. Employing particles of nanometer dimension suspended in solution as nanofluid shows considerable increase in the nanofluid thermal conductivity and heat transfer coefficient which result in increasing heat transfer and decreasing operational cost.

Keywords:

Heat Exchanger , Heat transfer coefficient , Nanofluid , Nusselt number