MHD convective heat transfer with temperature-dependent viscosity and thermal conductivity: a numerical investigation

Abstract

This paper considers numerical solutions to magneto hydrodynamics convective heat transfer over a permeable stretching wedge with thermal radiation and ohmic heating. Both the viscosity and thermal conductivity are assumed to vary as a linear function of the temperature, and dynamic viscosity is considered in a new form. Using an appropriate transformation, the governing partial differential equations are transformed into ordinary differential equations. Numerical solutions to these equations subject to corresponding boundary conditions are obtained by efficient numerical shooting technique coupled with Runge–Kutta–Fehlberg scheme. The effects of pertinent parameters are shown through tables and graphs, and meanwhile the associated transfer characteristics are analyzed in detail. The results show that: with the increase of viscosity variation parameter or the thermal conductivity, the local skin-friction coefficient increases but the local Nusselt number decreases. The increasing in viscosity variation parameter is to increase the velocity boundary layer thickness and decrease in the magnitude of the velocity gradient. Furthermore, thermal conductivity parameter has the same effect on the thermal boundary layer thickness and the temperature gradient.