Effect of inclination angle on the thermal-hydraulic characteristics and entropy generation of Al2O3–water nanofluid for in-tube turbulent flow
ISSN: 1708-5284
Article publication date: 4 April 2023
Issue publication date: 26 April 2024
Abstract
Purpose
Inclination angle has been reported to have an enhancing effect on the thermal-hydraulic characteristics and entropy of some thermal systems. Therefore, this paper aims to numerically investigate the effects of inclination angle, volume concentration and Reynolds number on the thermal and hydraulic characteristics and entropy generation rates of water-based Al2O3 nanofluids through a smooth circular aluminum pipe in a turbulent flow.
Design/methodology/approach
A constant heat flux of 2,000 Watts is applied to the circular surface of the tube. Reynolds number is varied between 4,000 and 20,000 for different volume concentrations of alumina nanoparticles of 0.5%, 1.0% and 2.0% for tube inclination angles of ±90o, ±60o, ±45o, ±30o and 0o, respectively. The simulation is performed in an ANSYS Fluent environment using the realizable kinetic energy–epsilon turbulent model.
Findings
Results show that +45o tube orientation possesses the largest thermal deviations of 0.006% for 0.5% and 1.0% vol. concentrations for Reynolds numbers 4,000 and 12,000. −45o gives a maximum pressure deviation of −0.06% for the same condition. The heat transfer coefficient and pressure drop give maximum deviations of −0.35% and −0.39%, respectively, for 2.0% vol. concentration for Reynolds number of 20,000 and angle ±90o. A 95%–99.8% and 95%–98% increase in the heat transfer and total entropy generation rates, respectively, is observed for 2.0% volume concentration as tube orientation changes from the horizontal position upward or downward.
Originality/value
Research investigating the effect of inclination angle on thermal-hydraulic performance and entropy generation rates in-tube turbulent flow of nanofluid is very scarce in the literature.
Keywords
Acknowledgements
This specific research did not receive any grant from funding agencies in the public, commercial or not-for-profit sectors.
Conflict of interest: On behalf of all the authors, the corresponding author declares no known conflict of interest.
Citation
Chinakwe, C., Adelaja, A., Akinseloyin, M. and Olakoyejo, O.T. (2024), "Effect of inclination angle on the thermal-hydraulic characteristics and entropy generation of Al2O3–water nanofluid for in-tube turbulent flow", World Journal of Engineering, Vol. 21 No. 3, pp. 549-568. https://doi.org/10.1108/WJE-12-2022-0487
Publisher
:Emerald Publishing Limited
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