International Scientific Journal


Packed beds are widely used in engineering applications due to their high specific surface area and good heat transfer characteristics. A grille-sphere composite packed bed is proposed previously and has been proved to have higher overall heat transfer coefficient than the simple cubic packing structure. In the present paper, the flow inhomogeneities in both the grille-sphere composite packed bed and the simple cubic packing are studied and the relationship between the flow inhomogeneity and the heat transfer characteristics is revealed by numerical simulations. The simulations are performed on ANSYS FLUENT software. The turbulence flow is modelled by the renormalization group k- model. Both dispersion of the velocity distribution and the residence time distribution are employed to assess the flow maldistribution. When the inlet velocity equals 2.17 m/s, the variance of the residence time distribution of the composite packed bed is 5.91% smaller than that of the simple cubic packing while the Nusselt number is 10.64% higher. The results indicate that less flow maldistribution can lead to heat transfer enhancement.
PAPER REVISED: 2020-04-21
PAPER ACCEPTED: 2020-05-01
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THERMAL SCIENCE YEAR 2020, VOLUME 24, ISSUE Issue 6, PAGES [3533 - 3542]
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© 2021 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence