Inherent irreversibility and thermal stability for steady flow of variable viscosity liquid film in a cylindrical pipe with convective cooling at the surface

Abstract

Purpose

The purpose of this paper is to investigate the inherent irreversibility and thermal stability in the flow of a variable viscosity fluid through a cylindrical pipe with convective cooling at the surface.

Design/methodology/approach

The non‐linear momentum and energy equations governing the flow are solved analytically using a perturbation method coupled with a special type of Hermite‐Padé approximation technique implemented numerically on MAPLE.

Findings

Expressions for dimensionless velocity and temperature, thermal criticality conditions and entropy generation number are obtained. A decrease in the fluid viscosity enhances both entropy generation rate and the dominant effect of heat transfer irreversibility near the wall

Originality/value

This paper presents the application of the second law of thermodynamics and a special type of Hermite‐Padé approximation technique to variable viscosity cylindrical pipe flow with convective cooling at the wall.

Citation

Makinde, O.D. and Maserumule, M. (2010), "Inherent irreversibility and thermal stability for steady flow of variable viscosity liquid film in a cylindrical pipe with convective cooling at the surface", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 20 No. 1, pp. 5-16. https://doi.org/10.1108/09615531011008091