An Experimental Investigation on Heat Transfer Enhancement in An Annulus with Rotating Outer Cylinder Using Nano Fluids

Abstract

Heat transfer augmentation for Taylor-Couette flows between concentric cylinders have been investigated experimentally. Due to its importance and widespread in wide industrial applications such as heat exchangers, reactors, well dinning, packed beds, compressors and gas turbines, chemical industries, etc. Different variables are investigated in the present work as follow, Rayleigh number (2×106 ≤ Ra ≤ 2×107), Taylors number (0 ≤ Ta ≤ 2.4×1010), Richardson Number (0.004 ≤ Ri ≤ 0.4) and nanoparticles volume fractions(φ) of Al2O3 with water base (0 % ≤ φ ≤ 0.225 %) in which prepared in two step method.  The enhancement in heat transfer was 16.5% to 24% due to rising the concentration of Nano fluids of Al2O3-pure water from 0% to 0.225%. Also, the Nusselt number increases with increasing Rayleigh and Richardson numbers. Finally, a correlation was deduced to describe the experimental work and linked the studied parameters with difference less than 13.5 %. The comparison between experimental work and previous works found a good agreement between them.