- Lage, J.L. and Bejan, A. and Georgiadis, J.G., Prandtl number effect near the onset of Benard convection in a porous medium,
International Journal of Heat and Fluid Flow, vol. 13 no. 4
pp. 408 - 411 [0142-727X(92)90011-W] .
(last updated on 2007/04/06)
This note focuses on Kladias and Prasad's claim that the critical Rayleigh number for the onset of Benard convection in an infinite horizontal porous layer increases as the Prandtl number decreases, and argues that the critical Rayleigh number (Rac) depends only on the Darcy number (Da), as linear stability analysis indicates. The two-dimensional steady-convection problem is then solved numerically to document the convection heat transfer effect of the Rayleigh number, Darcy number, Prandtl number, and porosity. The note concludes with an empirical correlation for the overall Nusselt number, which shows the effect of Prandtl number at above-critical Rayleigh numbers. The correlation is consistent with the corresponding correlation known for Benard convection in a pure fluid.
Porous materials;Porosity;Correlation methods;Mathematical models;