World Applied Sciences Journal 16 (11): 1638-1648, 2012 ISSN 1818-4952 © IDOSI Publications, 2012 Corresponding Author: Muhammad Ashraf, Centre for Advanced Studies in Pure and Applied Mathematics, Bahauddin Zakariya University, Multan, Pakistan 1638 Viscous Dissipation and Radiation Effects in MHD Stagnation Point Flow towards a Stretching Sheet with Induced Magnetic Field Kashif Ali, Muhammad Ashraf, Shahzad Ahmad and Kiran Batool Centre for Advanced Studies in Pure and Applied Mathematics, Bahauddin Zakariya University, Multan, Pakistan Abstract: In this paper we present the numerical study of steady laminar two dimensional nonlinear MHD stagnation point flow and heat transfer of an incompressible viscous fluid towards a stretching sheet, taking the induced magnetic field, viscous dissipation and radiation effects into consideration. The study reveals that the viscous dissipation may cause thermal reversal near the surface which is supported by the stretching parameter of the sheet when greater than unity and the Prandtl number as well. On the other hand, an opposite effect is observed for both the magnetic parameter and the radiation number. Key words: Stagnation point flow • thermal reversal • stretching sheet • radiation • MHD • finite difference method INTRODUCTION Hydromagnetic stagnation point flows with thermal effects have applications in many manufacturing processes in industry and engineering. These applications include boundary layers along material handling conveyers, the aerodynamic extrusion of plastic sheets, blood flow problems, the cooling of an infinite metallic plate in a cooling bath, textile and paper industries etc. The classical two dimensional stagnation point flow impinging on a flat plate was first considered by Hiemenz [1]. The flow of an electrically conducting fluid past a porous substrate attached to the flat plate with Beavers-Joseph boundary condition under the influence of a uniform transverse magnetic field was investigated by Jat and Santosh [2] using similarity transformation method. Ishak et al . [3] discussed the problem of steady two dimensional incompressible stagnation point flow towards a stretching sheet with variable surface temperature. Fang and Zhang [4] studied the problem of a transverse magnetic field to contain the vorticity over a shrinking sheet. Fang et al. [5] and Fang & Zhang [6] discussed the problem of mass and heat transfer characteristics on flow generated by a shrinking sheet. Kumaran et al. [7] analyzed the MHD boundary layer flow of an electrically conducting fluid over a stretching permeable surface with suction/ injection. Kumaran et al . [8] studied the problem of two dimensional stagnation point flow in a porous medium. Hassanien and Al Arabi [9] presented the problem of boundary layer unsteady mixed convection flow near the stagnation point on a heated vertical plate through a porous medium. Hayat et al. [10] investigated MHD stagnation point flow and heat transfer through a porous space bounded by a permeable surface. The problem of two dimensional steady laminar MHD Hiemenz forced flow over a flat plate through porous medium was solved by Kechil and Hashim [11]. Ali et al . [12] discussed steady two dimensional MHD stagnation point flow and heat transfer towards a stretching sheet with induced magnetic field by using shooting method. The numerical solution of MHD steady laminar two dimensional boundary layer stagnation flow of a viscous incompressible electrically conducting fluid over a stretching sheet with induced magnetic field was investigated by Ali et al . [13] using Keller-box method. Anwar et al . [14] studied the MHD two dimensional boundary layer flow of an electrically conducting forced convection liquid metal fluid flow with induced magnetic field effects. Nadeem and Akbar [15] considered the problem of two dimensional peristaltic flow of an incompressible electrically conducting Johnson Segalman fluid in a vertical asymmetric channel which possesses the effects of induced magnetic field. Very little attention has been paid to the boundary layer flow and heat transfer taking the effect of the induced magnetic field and thermal radiation into consideration. For example, Kumari et al. [16] considered the MHD flow and heat transfer over a stretching surface by considering the effect of the