## THERMAL SCIENCE

International Scientific Journal

### EFFECTS OF THERMAL RADIATION AND HEAT TRANSFER OVER AN UNSTEADY STRETCHING SURFACE EMBEDDED IN A POROUS MEDIUM IN THE PRESENCE OF HEAT SOURCE OR SINK

**ABSTRACT**

The effects of thermal radiation and heat transfer over an unsteady stretching surface embedded in a porous medium in the presence of heat source or sink are studied. The governing time dependent boundary layer equations are transformed to ordinary differential equations containing radiation parameter, permeability parameter, heat source or sink parameter, Prandtl number, and unsteadiness parameter. These equations are solved numerically by applying Nachtsheim-Swinger shooting iteration technique together with Rung-Kutta fourth order integration scheme. The velocity profiles, temperature profiles, the skin friction coefficient, and the rate of heat transfer are computed and discussed in details for various values of the different parameters. Comparison of the obtained numerical results is made with previously published results.

**KEYWORDS**

PAPER SUBMITTED: 2009-06-26

PAPER REVISED: 2010-03-16

PAPER ACCEPTED: 2010-03-25

**THERMAL SCIENCE** YEAR

**2011**, VOLUME

**15**, ISSUE

**2**, PAGES [477 - 485]

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