Abstract
Recent numerical studies of variable porosity and thermal dispersion effects on natural convection in porous media are summarized. This includes natural convection in a packed rectangular cavity heated from the side and heated from below, as well as natural convection from a heated horizontal cylinder embedded in an enclosed porous cavity. Numerical results show that both variable porosity and thermal dispersion effects increase the temperature gradient adjacent to the wall resulting in the enhancement of surface heat flux. These effects become important when the dimensionless particle diameter is increased. The numerical results show that the thermal dispersion effect on Nusselt number in natural convection in porous media is small. The Prandtl number effect on Nusselt number is also small for Prandtl number greater than one; its effect decreases as the Prandtl number decreases from one. A comparison of theory and experiments shows that the calculated Nusselt numbers with variable porosity and thermal dispersion effects taken into consideration agree the best with experimental data.
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© 1991 Springer Science+Business Media Dordrecht
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Cheng, P., Hsiao, SW., Chen, CK. (1991). Natural Convection in Porous Media with Variable Porosity and Thermal Dispersion Effects. In: Kakaç, S., Kilkiş, B., Kulacki, F.A., Arinç, F. (eds) Convective Heat and Mass Transfer in Porous Media. NATO ASI Series, vol 196. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-3220-6_17
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DOI: https://doi.org/10.1007/978-94-011-3220-6_17
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