the presence of heat generation,

Abstract This paper presents the study of steady two-dimensional mixed convection boundary layer flow and heat transfer of a Jeffrey fluid over a stretched sheet immersed in a porous medium in the presence of a transverse magnetic field. The governing partial differential equations are reduced to nonlinear ordinary differential equations with the aid of similarity transformation, which are then solved numerically using an implicit finite difference scheme. The effects of some of the embedded parameters, such as Deborah number β, magnetic parameter M, mixed convection parameter λ, porosity parameter γ and Prandtl number Pr, on the flow and heat transfer characteristics, are given in forms of tables and graphs. & 2017 National Laboratory for Aeronautics and Astronautics. Production and hosting by Elsevier B.V.

This is an open access article under the CC BY-NC-ND license

(http://creativecommons.org/licenses/by-nc-nd/4.0/).

1. Introduction

Flow of non-Newtonian fluid over stretching sheet has caught researchers’ attention in the last few decades due to its important practical applications, mainly in manufactur- ing and industry processes. For instance, in the extrusion of

r Aeronautics and Astronautics. Produ mons.org/licenses/by-nc-nd/4.0/).

7

6 6528.

(Kartini Ahmad).

onal Laboratory for Aeronautics

polymer process, the extrudate from the die is generally drawn and simultaneously stretched into sheet of desired thickness, and is then solidified. The final quality of the sheet depends mainly on the extensibility of the sheet and rate of heat transfer. Therefore, the cooling procedure has to be monitored adequately. To the best knowledge of the authors, the boundary layer flow over a moving horizontal sheet was first initiated by Sakiadis [1], who developed the flow field due to a flat surface. His work was later extended by Crane [2] to a stretching sheet, for the two-dimensional

ction and hosting by Elsevier B.V. This is an open access article under the

Nomenclature

a,b constant B0 uniform magnetic field Cf skin friction coefficient f dimensionless stream function g acceleration to gravity Grx local Grashof number k thermal conductivity M magnetic parameter Nux local Nusselt number Pr Prandtl number qw wall heat flux Rex local Reynolds number T fluid temperature Tw(x) temperature of the stretching sheet T∞ ambient temperature u,v velocity components along the x and y directions,