Brazilian Journal of Chemical Engineering
On-line version ISSN 0104-6632
KHAN, W. A. and GORLA, R. S. R.. Second law analysis for free convection in non-newtonian fluids over a horizontal plate embedded in a porous medium: (prescribed heat flux). Braz. J. Chem. Eng. [online]. 2012, vol.29, n.3, pp. 511-518. ISSN 0104-6632. http://dx.doi.org/10.1590/S0104-66322012000300008.
Second law characteristics of heat transfer and fluid flow due to free convection of non-Newtonian fluids over a horizontal plate with prescribed surface heat flux in a porous medium are analyzed. Velocity and temperature fields are obtained numerically using an implicit finite difference method under the similarity assumption and these results are used to compute the entropy generation rate Ns, irreversibility ratio φ and the Bejan number Be for both Newtonian and non-Newtonian fluids. The effects of power-law index n, heat flux variation parameter λ , and modified duty parameter, G on the dimensionless entropy generation rate Ns, and the Bejan number Be are investigated and presented graphically.
Keywords : Second law; Free convection; Non-Newtonian fluids; Porous medium; Plate.