O.D. Makinde and E. Osalusi

Applied Mathematics Department, University of Limpopo,
Private Bag X1106, Sovenga 0727, South Africa.

Received: 10 March 2005 / Accepted: 16 May 2005 / Published: 19 May 2005

Abstract: The entropy generation rate in a laminar flow through a channel filled with saturated porous media is investigated. The upper surface of the channel is adiabatic and the lower wall is assumed to have a constant heat flux. The Brinkman model is employed. Velocity and temperature profiles are obtained for large Darcy number D_a and used to obtain the entropy generation number and the irreversibility ratio. Generally, our result shows that heat transfer irreversibility dominates over fluid friction irreversibility (i.e. 0≤φ<1), and viscous dissipation has no effect on the entropy generation rate at the centerline of the channel.

Keywords: laminar flow; porous medium; entropy generation; irreversibility ratio.