Experimental Investigation on Heat Transfer Enhancement of Al2O3/Water Nanofluid with Combination of Circular Ring and Twisted Tape Inserts

Author(s): D.Mala, S. Sendhilnathan, B. Amritha

Abstract: An investigation is made experimentally with an attempt to enhance the rate of heat transfer of Al2O3 nanofluid in a heat exchanger with twisted tape insert. The heat transfer and the corresponding friction factors needed for performance analysis are determined at variable operating conditions of the heat exchangers with particle volume concentration of 0.1% , 0.3% and 0.6% and twist ratios ranging between 1.25 and 5. Experimental data are obtained at flow Reynolds number ranging from 767 to 2301. The Nusselt number of entire pipes for 0.6% concentrations of nanofluid with twisted tape inserts is enhanced by 147.85 % compared to water while the friction factor is increased by 7.6 times compared to water with twisted tape insert of TR = 1.25. Correlations are developed to estimate the Nusselt number and friction factor. The results of the investigation indicated significant improvement in the performance parameters of the heat exchanger with a rise in volume concentration of the nanoparticle.