Title

Unsteady flow and heat transfer in a thin film of Ostwald-de Waele liquid over a stretching surface

Authors

Authors

K. Vajravelu; K. V. Prasad;C. O. Ng

Comments

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Abbreviated Journal Title

Commun. Nonlinear Sci. Numer. Simul.

Keywords

Thin film flow; Heat transfer; Variable fluid property; Power-law fluid; Viscous dissipation; Numerical method; POWER-LAW FLUID; VISCOELASTIC FLUID; SHEET; PLATE; Mathematics, Applied; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas; Physics, Mathematical

Abstract

In this paper, the effects of viscous dissipation and the temperature-dependent thermal conductivity on an unsteady flow and heat transfer in a thin liquid film of a non-Newtonian Ostwald-de Waele fluid over a horizontal porous stretching surface is studied. Using a similarity transformation, the time-dependent boundary-layer equations are reduced to a set of non-linear ordinary differential equations. The resulting five parameter problem is solved by the Keller-Box method. The effects of the unsteady parameter on the film thickness are explored numerically for different values of the power-law index parameter and the injection parameter. Numerical results for the velocity, the temperature, the skin friction and the wall-temperature gradient are presented through graphs and tables for different values of the pertinent parameter. One of the important findings of the study is that the film thickness increases with an increase in the power-law index parameter (as well as the injection parameter). Quite the opposite is true with the unsteady parameter. Furthermore, the wall-temperature gradient decreases with an increase in the Eckert number or the variable thermal conductivity parameter. Furthermore, the surface temperature of a shear thinning fluid is larger compared to the Newtonian and shear thickening fluids. The results obtained reveal many interesting behaviors that warrant further study of the equations related to non-Newtonian fluid phenomena, especially the shear-thinning phenomena. (C) 2012 Elsevier B.V. All rights reserved.

Journal Title

Communications in Nonlinear Science and Numerical Simulation

Volume

17

Issue/Number

11

Publication Date

1-1-2012

Document Type

Article

Language

English

First Page

4163

Last Page

4173

WOS Identifier

WOS:000306199300016

ISSN

1007-5704

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