Buoyancy effect on MHD flow of nanofluid over a stretching sheet in the presence of thermal radiation

In this paper, heat transfer of a steady, incompressible water based nanofluid flow over a stretching sheet in the presence of transverse magnetic field with thermal radiation and buoyancy effects are investigated. A similarity transformation is used to reduce the governing momentum and energy equations into non-linear ordinary differential equations. The resulting differential equations with the appropriate boundary conditions are solved by shooting iteration technique together with fourth-order Runge-Kutta integration scheme. Analytical solutions are presented in terms of hypergeometric function for the special case of horizontal stretching sheet. The effects of the physical parameters on the flow and heat transfer characteristics are presented through graphs and analysed for Cu-metal and Cu-oxide nanoparticles. The values of skin friction coefficient and the reduced Nusselt number are calculated and presented through tables. Furthermore, the limiting cases are obtained and are found to be in good agreement with the previously published results. (C) 2014 Elsevier B.V. All rights reserved.