**Second law analysis of laminar flow in a channel filled
with saturated porous media: a numerical solution**

**Kamel Hooman ^{1}, Arash Ejlali^{2}**

^{1} Mechanical Engineering Department, Persian Gulf University, Bushehr, Iran

E-mail: Hooman@pgu.ac.ir

^{2} Fix Equipment Lead Engineer, Namavaran Delvar Engng. & Construction Company, Tehran, Iran

*Received: 2 November 2005 / Accepted: 8 December 2005 / Published: 9 December 2005*

**Abstract:**
This paper investigates entropy generation due to forced convection
in a porous medium sandwiched between two parallel plates one of them
being subjected to a uniform heat flux and the other one insulated.
Our results showed that viscous dissipation will affect the entropy
generation rate at the centerline of the channel since viscous dissipation
is a quadratic function of velocity [1-3]. Neglecting the Darcy dissipation
term in comparison with the terms added by Al-Hadrami et al. [4], will lead
to the misunderstanding that fluid friction has no effect on the entropy
generation rate at the tube centerline where the velocity derivative
vanishes due to symmetry. Though the term added by [4] is O(Da) compared
to the Darcy term one should not drop it unless the clear flow solution
is sought [5-7]. Moreover, as stated by Nield [1], one should not use just
the term involving velocity derivatives, as some authors have done in the past,
for example [8-11]. Though in this paper the viscous dissipation effects
in the energy equation are neglected, we have take them into account
when it came to the entropy generation analysis.

**Keywords:**
porous medium; forced convection; entropy generation; viscous dissipation.

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