Heat and Mass Transfer for MHD Viscoelastic Fluid Flow over a Vertical Stretching Sheet with Considering Soret and Dufour Effects

Mohamed Ali,Mohammad Mehdi Rashidi,Peyman Rostami,Behnam Rostami,Gong-Nan Xie

doi:10.1155/2015/861065

Abstract

The homotopy analysis method (HAM) with two auxiliary parameters is employed to examine heat and mass transfer in a steady two-dimensional magneto hydrodynamic viscoelastic fluid flow over a stretching vertical surface by considering Soret and Dufour effects. The two-dimensional boundary-layer governing partial differential equations are derived by considering the Boussinesq approximation. The highly nonlinear ordinary differential forms of momentum, energy, and concentration equations are obtained by similarity transformation. These equations are solved analytically in the presence of buoyancy force. The effects of different involved parameters such as magnetic field parameter, Prandtl number, buoyancy parameter, Soret number, Dufour number, and Lewis number on velocity, temperature, and concentration profiles are plotted and discussed. The effect of the second auxiliary parameter is also illustrated. Results show that the effect of increasing Soret number or decreasing Dufour number tends to decrease the velocity and temperature profiles (increase in Sr cools the fluid and reduces the temperature) while enhancing the concentration distribution.

Highlights

The analysis of the flow field in a boundary-layer near a stretching sheet is an important part in fluid dynamics and heat transfer
Afify [5] has shown that when heat and mass transfer occurred in a moving fluid, the energy flux can be generated by a composition gradient, namely, the Dufour or diffusionthermo effect, and the mass fluxes developed by the temperature gradients are called the Soret or thermal-diffusion effect
Heat and mass transfer with hydrodynamic slip over a moving plate in porous media was investigated by Hamad et al [6] via Runge-Kutta-Fehlberg fourth-fifth order method

Summary

Introduction

The analysis of the flow field in a boundary-layer near a stretching sheet is an important part in fluid dynamics and heat transfer. Afify [5] has shown that when heat and mass transfer occurred in a moving fluid, the energy flux can be generated by a composition gradient, namely, the Dufour or diffusionthermo effect, and the mass fluxes developed by the temperature gradients are called the Soret or thermal-diffusion effect. In their numerical study they have used the Soret and Dufour effects of a steady flow due to a rotating disk in the presence of viscous dissipation and ohmic heating. The heat transfer of mixed convection of vertically moving surface in an ambient stagnant fluid was reported by Ali and Al-Yousef [7, 8] and the effect of variable viscosity of mixed convection was studied by Ali [9]

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Conclusion