Table of Contents
Journal of Thermodynamics
Volume 2013, Article ID 234264, 10 pages
Research Article

Second Law Analysis of Laminar Flow in a Circular Pipe Immersed in an Isothermal Fluid

Infotech Enterprises Limited, Plot No. 2, IT Park, Nanakramguda, Manikonda, Gachibowli, Hyderabad, Andhra Pradesh 500032, India

Received 1 September 2013; Accepted 28 October 2013

Academic Editor: Felix Sharipov

Copyright © 2013 Vishal Anand and Krishna Nelanti. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Entropy generation and pumping power to heat transfer ratio (PPR) of a laminar flow, for a circular tube immersed in an isothermal fluid, are studied analytically in this paper. Two different fluids, namely, water and ethylene glycol, are chosen to study the influence of fluid properties on entropy generation and PPR. The expressions for dimensionless entropy generation, Bejan number and PPR are derived in a detailed way and their variations with Reynolds number, external Biot number, and the dimensionless temperature difference are illustrated. The results of the analysis are compared with those for a laminar flow in a circular tube with uniform wall temperature boundary condition. Finally, a criterion is established to determine which type of thermal boundary conditions is more suitable for a particular fluid, with respect to its influence on entropy generation.