Open Access Research

Stagnation-point flow over a permeable stretching/shrinking sheet in a copper-water nanofluid

Norfifah Bachok1, Anuar Ishak2*, Roslinda Nazar2 and Norazak Senu1

Author Affiliations

1 Department of Mathematics and Institute for Mathematical Research, Universiti Putra Malaysia, Serdang, Selangor, 43400 UPM, Malaysia

2 School of Mathematical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor, 43600 UKM, Malaysia

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Boundary Value Problems 2013, 2013:39  doi:10.1186/1687-2770-2013-39

Published: 26 February 2013

Abstract

An analysis is carried out to study the heat transfer characteristics of steady two-dimensional stagnation-point flow of a copper (Cu)-water nanofluid over a permeable stretching/shrinking sheet. The stretching/shrinking velocity and the ambient fluid velocity are assumed to vary linearly with the distance from the stagnation-point. Results for the skin friction coefficient, local Nusselt number, velocity as well as the temperature profiles are presented for different values of the governing parameters. It is found that dual solutions exist for the shrinking case, while for the stretching case, the solution is unique. The results indicate that the inclusion of nanoparticles into the base fluid produces an increase in the skin friction coefficient and the heat transfer rate at the surface. Moreover, suction increases the surface shear stress and in consequence increases the heat transfer rate at the fluid-solid interface.

MSC: 34B15, 76D10.

Keywords:
nanofluid; stagnation-point; stretching/shrinking sheet; suction/injection; heat transfer; dual solutions