1 3 J Braz. Soc. Mech. Sci. Eng. (2017) 39:3039–3050 DOI 10.1007/s40430-017-0759-z TECHNICAL PAPER Effects of inclined Lorentz forces on boundary layer flow of Sisko fluid over a radially stretching sheet with radiative heat transfer J. Ahmed 1 · A. Shahzad 1 · A. Begum 2 · R. Ali 3 · N. Siddiqui 1 Received: 14 September 2016 / Accepted: 8 March 2017 / Published online: 25 March 2017 © The Brazilian Society of Mechanical Sciences and Engineering 2017 1 Introduction The study of magnetohydrodynamics (MHD) has attracted considerable attention of many researchers due to its numerous applications such as, plasma confine- ment, purification of crude oil, MHD power generator, cooling of nuclear reactor, etc. Hydromagnetic boundary layers are observed in many technical systems employ- ing liquid metal and plasma flow transverse of magnetic fields. In these situations, the flow control can be real- ized by the Lorentz force. Pavlov [1] analyzed the MHD boundary layer flow of an incompressible viscous fluid and obtained the exact analytical solution. Ellahi et al. [2] discussed the analytical solutions for MHD flow in a third-grade fluid with variable viscosity. Ahmed et al. [3] analyzed the convective heat transfer of an MHD Jaffrey fluid over a stretching sheet and obtained the exact solu- tion for PST and PHF cases, they concluded that the heat transfer rate decreases due to increase in magnetic field in both cases. Borrelli et al. [4] discussed the 3D MHD stagnation point flow of a Newtonian fluid and obtained the numerical solution. Ellahi [5] studied the effects of MHD and temperature-dependent viscosity on the flow of non-Newtonian nanofluid in a pipe. The effects of trans- verse magnetic field on rotating micropolar fluid between parallel pates with heat transfer have been discussed by Rashid et al. [6]. Hakeem et al. [7] discussed the influ- ence of inclined Lorentz forces on boundary layer flow of Casson fluid over an impermeable stretching sheet with heat transfer, they found that increasing values of aligned angle of magnetic field lead to decrease of the skin friction coefficient and the Nusselt number. Bor- relli et al. [8] studied the effect of a non-uniform external magnetic field on the 3D stagnation-point flow. Recently many researchers [9–19] focused on MHD boundary Abstract The inclined magnetic field effect on the bound- ary layer flow of Sisko fluid model over a radially stretch- ing sheet is investigated. The effects of viscous dissipation and thermal radiations are also taken into account. It is assumed that the magnetic field is applied with an inclined angle γ which varies from 0 ◦ to 90 ◦ . The suitable transfor- mations are used to convert the governing partial differ- ential equations into a set of non-linear coupled ordinary differential equations. The numerical solution of the gov- erning problem is obtained by using fourth-order Runge– Kutta method with shooting technique. The obtained results for velocity and temperature are expressed through graphs against various emerging physical parameters such as magnetic parameter, angle of inclination, Prandtl number, radiation number, Eckert number and material parameter of the Sisko fluid for different values of power law index. It is found that increasing value of aligned angle strength- ens the magnetic field and decreases the velocity profile and enhances the heat transfer rate. Further, the numerical values are given in tabular form for the local skin friction coefficient and the local Nusselt number. Keywords Boundary layer flow · Sisko fluid · Inclined magnetic field · Viscous dissipation Technical editor: Cezar Negrao. * R. Ali alian.qau@gmail.com 1 Department of Basic Sciences, University of Engineering and Technology, Taxila 47050, Pakistan 2 Karakoram International University, Gilgit-Baltistan, Pakistan 3 University of Central Asia, Naryn, Kyrgyzstan