Impacts of binary chemical reaction with activation energy on unsteady flow of magneto-Williamson nanofluid

摘要

The current review aims to study the combined effects of variable magnetic field and heat generation/absorption on unsteady flow of non-Newtonian Williamson fluid generated by a stretching cylinder in the presence of nano particles. An important prospective of this endeavour is to incorporate the impacts of binary chemical reaction and activation energy for revised Buongiorno's model of nanofluid in view of their improved heat transfer. The notion of Boussinesq-approximations is utilized to model the leading equations of momentum, thermal energy and nanoparticle concentration for Williamson fluid. We have employed suitable non-dimensional quantities to alter the leading partial differential equations (PDEs) into a set of ordinary differential equation (ODES). The numerical simulation is conducted with the help of Runge-Kutta Fehlberg scheme coupled with shooting iteration procedure. The analysis of the obtained results revealed that the assumed physical model is significantly influenced by the key physical parameters, like, magnetic parameter, chemical reaction parameter, activation energy parameter, heat generation/absorption parameter, Brownian motion and thermophoresis parameter. The physical significance of above-mentioned physical parameters on nanofluid velocity, temperature and concentration is argued and exhibited through graphs. The cardinal physical intimation of obtained results is that the nanoparticles concentration enhances with higher activation energy parameter. Further, it is perceived from these results that the rate of heat transfer over the cylinder surface de-escalates with an increase in the reaction rate parameter. It is noted that an augmentation in thermophoresis parameter leads to a rise in nanofluid temperature. (C) 2018 Published by Elsevier B.V.