Effects of slip and heat generation/absorption on MHD stagnation flow of nanofluid past a stretching/shrinking surface with convective boundary conditions

The objective of the present study is to analyze the effects of velocity slip and heat generation/absorption on magnetohydrodynamic (MHD) stagnation-point flow and heat transfer over a stretching/shrinking surface, with convective boundary conditions, in the presence of nanoparticle fractions. The effects of Brownian motion and thermophoresis are also considered. The velocity, temperature and nanoparticle concentration profiles are analyzed with respect to the involved parameters, namely, slip parameter (delta), magnetic parameter (M), source/sink parameter (lambda), Brownian motion parameter (Nb), thermophoresis parameter (Nt), Prandtl number (Pr), Lewis number (Le), Biot number (gamma) and ratio of the rate constants of stretching/shrinking velocity to the free stream velocity (alpha). The numerical results indicate that for the stretching sheet, the velocity at a point decreases with the increase in the values of delta and M; whereas both temperature and nanoparticle concentration increase with the increase in delta and M. It is also observed that the temperature of the fluid increases with the increase in heat source parameter (i.e. lambda > 0). Different from a stretching sheet, it is found that for a shrinking sheet the solutions are non-unique. A comparative study between the previously published results and the present results for a special case is found to be in good agreement. (C) 2013 Elsevier Ltd. All rights reserved.