Title: Second law analysis of a gravity-driven liquid film flowing along an inclined plate subjected to constant wall temperature

Authors: Abdullah I. Al-Ahmed; Ramazan Kahraman; Ahmet Z. Sahin; Mohammad Hasan Arshad

Addresses: Saudi Aramco Total Refinery & Petrochemical (SATORP), Al-Ahsa 31518, Saudi Arabia ' Chemical Engineering Department, College of Engineering, Qatar University, P.O. Box 2713, Doha, Qatar ' Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, KFUPM Box 1461, Dhahran 31261, Saudi Arabia ' Chemical Engineering Department, College of Engineering, Qatar University, P.O. Box 2713, Doha, Qatar

Abstract: The second law analysis of a gravity-driven liquid having temperature-dependent viscosity and flowing along an inclined heated plate was studied. The computational fluid dynamics (CFD) package FLUENT was used to obtain the velocity and temperature gradients, and the results were used to determine the entropy generation rate. Different cases of inclination angle and dimensionless parameters were investigated. There is significant difference in the entropy generation rate magnitude in comparison to the entropy generation for constant physical properties case. The entropy generation rate has its maximum value near the plate surface and decreases sharply towards the free surface. It also decreases in the longitudinal axial direction due to the decrease in the temperature difference between the plate and film temperate towards the downstream. Changing the inclination angle has no significant effect in the entropy generation rate except near the plate surface.

Keywords: second law analysis; thermodynamics; inclined plate; entropy generation; gravity-driven flow; temperature-dependent viscosity; heated plate; computational fluid dynamics; CFD; fluid flow.

DOI: 10.1504/IJEX.2014.060280

International Journal of Exergy, 2014 Vol.14 No.2, pp.156 - 178

Received: 10 Oct 2012
Accepted: 11 Mar 2013
Published online: 02 Mar 2015 *

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