Thermal decomposition of unsteady non-Newtonian MHD Couette flow with variable properties

Purpose – The purpose of this paper is to investigate the unsteady magnetohydrodynamic (MHD) Couette flow of an electrically conducting incompressible non-Newtonian third grade reactive fluid with temperature-dependent variable viscosity and thermal conductivity properties under isothermal surface conditions. Design/methodology/approach – The coupled non-linear partial differential equations for momentum and energy balance governing the transient problem are obtained and tackled numerically using a semi-discretization finite difference technique. Findings – The effects of various embedded thermophysical parameters on the velocity and temperature fields including skin friction, Nusselt number and thermal stability conditions are presented graphically and discussed quantitatively. Practical implications – The approach is applicable to modelling the complex physical phenomenon in MHD lubrications that occurs in numerous areas of engineering and industrial processes. Originality/value – This paper may be of industrial and engineering interest especially in understanding the combined effects of unsteadiness, variable thermophysical properties and magnetic field on the thermal stability condition for a reactive non-Newtonian third grade fluid under Couette flow scenario.