Dual solutions of stagnation-point flow of a nanofluid over a stretching surface

Peri K Kameswaran,Prabhala Vsn Murthy,Chetteti Ramreddy,Precious Sibanda

doi:10.1186/1687-2770-2013-188

Peri K Kameswaran, Prabhala Vsn Murthy + Show 2 more

Open Access

https://doi.org/10.1186/1687-2770-2013-188

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Abstract

Abstract The paper discusses the effects of homogeneous-heterogeneous reactions on stagnation-point flow of a nanofluid over a stretching or shrinking sheet. The model presented describes mass transfer in copper-water and silver-water nanofluids. The governing system of equations is solved numerically, and the study shows that dual solutions exist for certain suction/injection, stretching/shrinking and magnetic parameter values. Comparison of the numerical results is made with previously published results for special cases.

Highlights

Problems involving fluid flow over stretching or shrinking surfaces can be found in many manufacturing processes such as in polymer extrusion, wire and fiber coating, foodstuff processing, etc
Heat transfer over a stretching or shrinking sheet subject to an external magnetic field, viscous dissipation and joule effects was studied by Jafar et al [ ]
This article presents a study of homogeneous-heterogeneous reactions on MHD nanofluid stagnation point flow due to a stretching or shrinking sheet

Summary

Introduction

Problems involving fluid flow over stretching or shrinking surfaces can be found in many manufacturing processes such as in polymer extrusion, wire and fiber coating, foodstuff processing, etc. The stagnation-point flow over a stretching or shrinking sheet in a nanofluid was investigated by Bachok et al [ ] They showed that adding nanoparticles to a base fluid increased the skin friction and heat transfer coefficients. This article presents a study of homogeneous-heterogeneous reactions on MHD nanofluid stagnation point flow due to a stretching or shrinking sheet. The non-dimensional parameters in equations ( )-( ) are the magnetic parameter M, the Schmidt number Sc, the measure of the strength of the homogeneous reaction K , the ratio of diffusion coefficients δ, the mass transfer parameter fw, with fw > for suction and fw < for injection, the measure of the strength of the heterogeneous reaction Ks, the Reynolds number Re and λ = Uw/U∞ is the stretching parameter, with λ > for stretching and λ < for shrinking, respectively.

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