Thermophoresis and Brownian motion effects on magneto-convective heat transfer of viscoelastic nanofluid over a stretching sheet with nonlinear thermal radiation

Abstract

In this paper, the effects of magnetic field and non-linear thermal radiation on the boundary layer flow and heat transfer of a viscoelastic nanofluid past a stretching sheet in the presence of suction has been investigated. We considered the combined effects of thermophoresis, Brownian motion and viscous dissipation. Using similarity transformations, the governing equations are reduced to a system of nonlinear ordinary differential equations with associated boundary conditions. The reduced non-linear system of differential equations has been solved numerically by Runge–Kutta–Fehlberg fifth-order method with a shooting technique. The effects of the magnetic field, the Prandtl number, the viscous dissipation, the Brownian motion parameter, the thermal buoyancy parameter, the viscoelastic parameter, the thermophoresis parameter, and the Lewis number on the local Nusselt and local Sherwood numbers are analysed. The study shows that the temperature in the thermal boundary layer increases with an increase in the value of Lewis number, wall temperature excess ratio parameter, Brownian motion parameter, thermophoresis number, magnetic parameter, and Eckert number, whereas velocity profile decreases near the stretching surface with an increase in the Prandtl number, magnetic parameter, Lewis number and suction number.