Effects of non-linearly variable heat flux and thermal radiation on heat transfer in MHD boundary layer flow over an unsteady permeable stretching sheet in Darcy porous medium

Abstract

In this analysis, the effects variable heat flux and thermal radiation on MHD flow and heat transfer over an unsteady permeable stretching sheet in a porous medium with mass suction/injection are investigated. The basic equations of flow are converted to self-similar ordinary equations adopting suitable similarity transformations. Shooting method is used to obtain numerical solutions of the transformed self-similar equations. Simultaneous effects of variable heat flux, thermal radiation, magnetic field and resistance for porous medium on the unsteady flow and heat transfer are obtained. It is found that for magnetic field and the medium of flow being porous, the velocity decreases and temperature increases. Also, mass suction has similar effect on the velocity profile. Temperature and thermal boundary layer thickness decrease with unsteadiness, Prandtl number and variable heat flux with high rate of heat transfer from the sheet to the ambient fluid. Whereas, for stranger magnetic field the heat transfer rate reduces. © 2017 Institute of Thermomechanics CAS, v.v.i.