Forced convective boundary layer flow of a nanofluid past a continuous stretching surface

Abstract

Nanofluid is an advanced kind of fluid containing small quantities of nanoparticles that are uniformly and stably suspended in a base liquid. It has a higher thermal conductivity and enhanced heat transfer coefficient than its base fluid. In this study, the steady forced convective boundary layer flow of a nanofluid past a continuous stretching surface with suction or injection and magnetic effect is investigated. This mathematical model describes the flow of nanofluid that incorporates the effects of Brownian motion and thermophoresis. The governing nonlinear partial differential equations are transformed into a system of nonlinear ordinary differential equations using similarity transformation which is then solved numerically using a finite difference scheme known as the Keller-box method. The numerical results obtained show that the value of the reduced Nusselt number decreases with the increasing value of the Brownian motion parameter, Nb and thermophoresis parameter, Nt. Whereas, the value of the reduced Sherwood number increases with Nt but decreases with Nb. It is also observed that the reduced Nusselt and Sherwood numbers decrease with an increase of the velocity stretching parameter, m, the magnetic parameter, Mn and the injection parameter, d > 0 . The suction parameter, d < 0 , on the other hand, tends to increase the skin friction coefficient, reduced Nusselt and Sherwood numbers. The results show that the Brownian motion and thermophoresis influence the flow characteristics of nanofluids by either warming the boundary layer or aggravating the collisions between the nanoparticles and molecules of the base fluid.