ISRN Thermodynamics

Volume 2012, Article ID 465864, 9 pages

http://dx.doi.org/10.5402/2012/465864

## Heat Transfer due to Magnetohydrodynamic Stagnation-Point Flow of a Power-Law Fluid towards a Stretching Surface in the Presence of Thermal Radiation and Suction/Injection

^{1}Department of Mathematics, Visva Bharati (A Central University), West Bengal, Santiniketan 731235, India^{2}Department of Mathematics, Bengal Institute of Technology and Management, West Bengal, Santiniketan 731236, India

Received 5 October 2012; Accepted 19 November 2012

Academic Editors: A. Ghoufi, S. Hashimoto, and B. Merinov

Copyright © 2012 Tapas Ray Mahapatra et al. 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.

#### Abstract

An analysis is made on the study of two-dimensional MHD (magnetohydrodynamic) boundary-layer stagnation-point flow of an electrically conducting power-law fluid over a stretching surface when the surface is stretched in its own plane with a velocity proportional to the distance from the stagnation-point in the presence of thermal radiation and suction/injection. The paper examines heat transfer in the stagnation-point flow of a power-law fluid except when the ratio of the free stream velocity and stretching velocity is equal to unity. The governing partial differential equations along with the boundary conditions are first brought into a dimensionless form and then the equations are solved by Runge-Kutta fourth-order scheme with shooting techniques. It is found that the temperature at a point decreases/increases with increase in the magnetic field when free stream velocity is greater/less than the stretching velocity. It is further observed that for a given value of the magnetic parameter , the dimensionless rate of heat transfer at the surface and decreases/increases with increase in the power-law index . Further, the temperature at a point in the fluid decreases with increase in the radiation parameter when free stream velocity is greater/less than the stretching velocity.