Effect of Axial Conduction on Laminar Forced Convective Heat Transfer Enhancement by Porous Inserts in Parallel Plate Channels


V. V. Satyamurty1 and D. Bhargavi2

Professor, Department of Mechanical Engineering, IIT Kharahpur, Kharahpur 721 302, India.

vvsmurty@mech.iitkgp.ernet.in

Res. Scholar, Department of Mechanical Engineering, IIT Kharahpur, Kharahpur 721 302, India.

bhargavi.math@gmail.com

ABSTRACT

The present investigation has been undertaken to assess the effect of axial conduction on heat transfer characteristics in the thermally developing region of a parallel plate channel with porous insert embedded to one wall of the channel. The fully developed flow field in the porous region corresponds to Darcy-Brinkman model and the clear fluid region to that of plane Poiseuille flow. The system is characterized by the parameters, Darcy number, Da, Peclet number, Pe and a porous fraction γp defined as ratio of the porous insert thickness to the channel wall spacing. The studies further quantify the effect of porous insert on heat transfer enhancement. Numerical solutions have been obtained for 0 ≤ γp ≤ 1.0, for Pe = 5, 25, 50, and 100 for one representative Darcy number, Da = 0.001. The optimum porous fraction (γp ≈ 0.8) for which maximum wall heat transfer occurs is independent of the Peclet number and remains the same for any desired length of the duct. The wall heat transfer plots given in the present investigation can conveniently be used in place of average Nusselt number.

Keywords: Axial conduction, Channels partially filled with porous material, Heat Transfer enhancement.


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