Numerical study of entropy analysis for electrical unsteady natural magnetohydrodynamic flow of nanofluid and heat transfer

This study deals with entropy analysis on natural convection flow of electrical magnetonanofluid over a permeable stretching sheet considering Brownian motion and thermophoresis diffusion effects. Additionally, the aspects of thermal radiation, viscous dissipation, chemical reaction and heat generation/absorption are introduced. The formulation is made by using the revised model of passively controlled boundary rather than actively, which is more realistic. Equations governing the flow are converted to a nonlinear couple of ordinary differential equations and then tackled through a numerical approach known as implicit finite difference scheme. Entropy generation and Bejan numbers are evaluated from the momentum, energy, and nanoparticle concentration equations due to stretching sheet. The impacts of embedded physical parameters on the fields are displayed with aids of tabular and graphs. vertical bar The results reveal that magnetic and electric fields have a reverse effect on the fluid velocity and the fluid temperature intensified with thermal radiation and viscous dissipation. Entropy generation enhances with the electric field, thermal radiation, and suction, but suppressed with Brownian motion and magnetic field. Bejan number is sensitive to an increase in viscous dissipation, heat generation, and chemical reaction. Comparison with previously published studied examined and performed are noticed to be in good agreement. (C) 2017 The Physical Society of the Republic of China (Taiwan). Published by Elsevier B.V. All rights reserved.