Conjugate MHD natural convection of hybrid nanofluids in a square enclosure containing a complex conductive cylinder
International Journal of Numerical Methods for Heat & Fluid Flow
ISSN: 0961-5539
Article publication date: 17 October 2022
Issue publication date: 20 January 2023
Abstract
Purpose
The purpose of this study is to investigate the enhancement and suppression of heat transfer for hybrid nanofluids (Cu–Al2O3/water) in a square enclosure containing a thermal-conductive cylinder when the Lorentz force is applied to the hybrid nanofluids.
Design/methodology/approach
Since the inner conductive cylinder in present research has a complex geometry, an in-house meshless method, namely, the local radial basis function (LRBF) method, is applied to solve the 2 dimensional (2D) incompressible Navier–Stokes equation in the fluid domain and Fourier heat conduction equation in solid domain. The solid–fluid interface remains the physical continuity of temperature and heat flux. Only the Lorentz force is considered for the presence of the magnetic field. The conjugate natural convection is assumed to be steady, thus only fully developed heat exchange from the nanofluids to solid or vice versa is comprehensively investigated.
Findings
It can be concluded that Lorentz force plays a more significant role than hybrid nanofluids in enhancing/suppressing heat transfer when the orientation of magnetic field is the same to the x direction. The thermal conductivity ratio can dramatically change the isotherms and streamlines as well as the mean value of the Nusselt number, resulting in totally different heat transfer phenomena. The included angle of magnetic field also has a significant effect on the heat transfer rate when it changes from horizontal to vertical.
Research limitations/implications
The constant thermo-physical properties of incompressible fluid and the 2D steady flow are considered in this study.
Originality/value
The conjugate MHD natural convection of hybrid nanofluids is numerically investigated by an in-house meshless LRBF method. The enhancement and suppression of heat transfer under the combined influence of the volume fraction of nanoparticles, Hartmann number and the thermal conductivity ratio are comprehensively investigated.
Keywords
Acknowledgements
The authors gratefully acknowledge the financial supports provided by the National Natural Science Foundation of China (Nos. 12102331, 52206053 and 52130603).
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Citation
Wang, T., Li, A., Xi, G. and Huang, Z. (2023), "Conjugate MHD natural convection of hybrid nanofluids in a square enclosure containing a complex conductive cylinder", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 33 No. 3, pp. 941-964. https://doi.org/10.1108/HFF-04-2022-0215
Publisher
:Emerald Publishing Limited
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