## THERMAL SCIENCE

International Scientific Journal

### MAGNETOHYDRODYNAMIC THIN FILM AND HEAT TRANSFER OF POWER LAW FLUIDS OVER AN UNSTEADY STRETCHING SHEET WITH VARIABLE THERMAL CONDUCTIVITY

**ABSTRACT**

This paper presents an investigation on the MHD thin film flow and heat transfer of a power law fluid over an unsteady stretching sheet. The effects of power law viscosity on a temperature field are taken into account with a modified Fourier’s law Proposed by Zheng by assuming that the temperature field is similar to the velocity field. The governing equations are reduced to a system of nonlinear ordinary differential equations. The numerical solutions are obtained by using the shooting method coupled with the Runge-Kutta method. The influence of the Hartmann number, the power law exponent, the unsteadiness parameter, the thickness parameter and the generalized Prandtl number on the velocity and temperature fields are presented graphically and analyzed. Moreover, the critical formula for parameters are derived which indicated that the magnetic field has no effect on the critical value.

**KEYWORDS**

PAPER SUBMITTED: 2013-05-27

PAPER REVISED: 2014-03-07

PAPER ACCEPTED: 2014-03-08

PUBLISHED ONLINE: 2014-04-05

**THERMAL SCIENCE** YEAR

**2016**, VOLUME

**20**, ISSUE

**6**, PAGES [1791 - 1800]

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