Entropy generation for forced convection in a porous channel with isoflux or isothermal walls

Ejlali²,

Appl. Math. Mech.-Engl. Ed.

2008

Self Cite

Entropy generation for thermally developing forced convection in a porous medium bounded by two isothermal parallel plates is investigated analytically on the basis of the Darcy flow model where the viscous dissipation effects had also been taken into account. A parametric study showed that decreasing the group parameter and the Péclet number increases the entropy generation while for the Brinkman number the converse is true. Heatline visualization technique is applied with an emphasis on Br<0 case where there is somewhere that heat transfer changes direction at some streamwise location to the wall instead of its original direction, i.e. from the wall.

Section: Resultssupporting

confidence: 78%

Section: Introductionmentioning

confidence: 99%

Entropy generation analysis of thermally developing forced convection in fluid-saturated porous medium

Ejlali²,

Appl. Math. Mech.-Engl. Ed.

2008

Self Cite

Int. J. of Pure and Appl. Math.

“…The analysis of entropy generation minimization in a thermal system was introduced by Bejan [1] and explained that this minimization improves the efficiency of a system by improving the exergy. Thereafter, several researchers have theoretically studied entropy generation in thermal and flow systems under many physical situations [2][3][4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Thermodynamics Analysis for a Reacting Couple Stress Fluid Flow Through a Vertical Channel

Adesanya¹,

Falade²,

Ukaegbu³

et al. 2017

In this paper, entropy generation rate in the flow of couple stress fluid undergoing exothermic chemical reaction through a porous vertical channel is studied by applying the second law of thermodynamics. A semi-analytical solution for the governing equations is obtained using Adomian decomposition method (ADM). The effects of couple stress parameter, internal heat generation parameter, Dufour number on the velocity, temperature distribution, entropy generation rate and Bejan number are investigated and the results were presented graphically. The results show that solutal diffusivity has significant effect on the entropy generation rate and irreversibility of heat in a couple stress fluid flow.

Journal of Industrial Mathematics

“…Hooman and Ejlali [10] dealt with entropy production for thermally developing dissipative forced convection in a porous tube. Hooman et al [11] studied entropy generation for forced convection in a porous channel with isoflux or isothermal walls. Makinde and Aziz [12] performed analytical and numerical analysis of the second law of thermodynamics for plane Poiseuille flow with asymmetric convective heat transfer taking variable fluid viscosity.…”

Section: Introductionmentioning

confidence: 99%

Entropy Analysis for MHD Generalised Couette Flow in a Composite Duct

Vyas

Ranjan

2015

This paper presents entropy analysis of electrically conducting Newtonian fluid flow inside a horizontal composite duct. The upper impermeable wall of the duct moves with a uniform velocity while the lower wall is porous strata of finite thickness with impermeable bottom. The upper wall and the impermeable bottom are at constant temperature but at different temperatures. The duct is divided into two regions: Region I of clear fluid and Region II of fluid saturated porous layer. Momentum and thermal regimes for clear and porous regions are matched at clear fluid-porous interface by employing suitable matching conditions. The governing equations are solved analytically. Analytical solutions obtained for velocity and temperature are utilized to compute entropy generation. The effects of pertinent parameter on temperature distribution, entropy generation, and Bejan number are portrayed graphically and discussed.