MHD stagnation point flow and heat transfer due to nanofluid towards a stretching sheet

In this paper we analyzed the effect of magnetic field on stagnation point flow and heat transfer due to nanofluid towards a stretching sheet. The transport equations employed in the analysis include the effect of Brownian motion and thermophoresis. The solution for the temperature and nanoparticle concentration depends on six parameters viz, velocity ratio parameter A, Prandtl number Pr. Lewis number Le, Brownian motion Nb, and the thermophoresis parameter Nt. Similarity transformation is used to convert the governing nonlinear boundary-layer equations to coupled higher order nonlinear ordinary differential equation. These equations were numerically solved using Runge-Kutta fourth order method with shooting technique. Numerical results are obtained for velocity, temperature and concentration distribution, as well as the skin friction coefficient, local Nusselt number and Sherwood number. The results indicate that the skin friction coefficient C-f and local Nusselt number increases with an increase in velocity ratio parameter A. Likewise, the local Sherwood number increases with an increase in both velocity ratio A and Lewis number Le. Besides, it is found that the heat transfer rate at the surface increases with the magnetic parameter when the free stream velocity exceeds the stretching velocity, i.e. A > 1, and it decreases when A < 1. A comparison with a previous study available in the literature has been done and we found an excellent agreement with them. (c) 2012 Elsevier Ltd. All rights reserved.