Hydromagnetic Electrically Conducting Flow Past a Continuously Moving

Inclined Plate with Heat and Mass Transfer

Rita Choudhury, Saswati Purkayastha

Department of Mathematics, Gauhati University, Guwahati-781014, Assam, India

*Corresponding Author E-mail: rchoudhury66@yahoo.in, saswati1001@gmail.com

ABSTRACT:

The hydromagnetic free convective fluid flow over a continuously moving inclined plate embedded on a porous medium has been investigated. The periodic transverse suction velocity is applied to the surface due to which the flow becomes unsteady. The visco-elastic fluid flow is characterized by Walters liquid (model B′). Analytical solution of the problem is obtained by using multi-parameter perturbation technique. The expressions for velocity field, temperature field, concentration field, shearing stress at the plate are derived analytically. The fluid velocity and shearing stress are illustrated graphically to observe the visco-elastic effects in combination with other flow parameters involved in the solution. Also the temperature and concentration fields are not significantly affected by the visco-elasticity in comparison with Newtonian fluid flow mechanism.

KEYWORDS: Free convection, Heat source, Hydromagnetic flow, Porous medium, Suction.

1. INTRODUCTION:

In processes such as drying, evaporation at the surface of a water body, energy transfer in a wet cooling tower and the flow in a desert cooler, heat and mass transfer occur simultaneously. Possible applications of this type of flow can be found in many industries. Representative applications of interest include: solidification of binary alloy and crystal growth, dispersion of dissolved materials or particulate water in flows, drying and dehydration operations in chemical and food processing plants and combustion of atomized liquid fuels. In our daily life, the combined heat and mass transfer phenomenon is observed in the formation of fog.

Combined heat and mass transfer problems in non-Newtonian fluid are of great importance in many operations in the chemical and engineering industries including coaxial mixers (Thibault and Tanguy 2002), blood oxygenators (Goerke et al. 2002), mild processing (Wang and Chem 2005), steady state tubular reactor and capillary column inverse gas chromatography devices (Vrentas and Vrentas 1996), mixing mechanisms (Shamlou and Edwards 1986), bubble-drop formation processes (Jarzebski and Malinowski 1986), dissolution processes (Elperin and Fominykh 2001) and cloud transport phenomena (Waslo and Gal-or 1971). Many liquids possess complex shear-stress relationship which deviate significantly from the Newtonian (Navier-Stokes) model.

The problem of boundary layer flow past a stretching sheet are extensively used in various technological processes like hot rolling, wire drawing, glass-fiber and paper production etc. The classical works done by Sakiadis (1961), Tsou et.al. (1967) and Crane (1970) have been continued by the researchers arising to extensive applications of such works and computational solutions have been presented to a wide spectrum of problems. Ericksen et al. (1966) have studied the combined heat and mass transfer on a moving continuous plate with suction or injection.

In this paper, we have studied the two dimensional steady free convective hydromagnetic boundary layer visco-elastic flow over a continuously moving inclined surface in presence of heat and mass transfer. The dissipation of energy has been also considered. The visco-elastic fluid flow is characterized by Walters liquid (Model B^/).

The constitutive equation for Walters liquid (Model B^/) is

5. CONCLUSIONS:

From the present study we can make the following conclusions:

§ The velocity field is considerably affected by the visco-elastic parameters.

§ The fluid velocity is enhanced with the increasing values of visco elastic parameter in comparison with the Newtonian fluid.

§ A declined trend of shearing stress is observed in case of increasing values of Grashof number Gr and heat source parameter S and magnetic parameter M in both Newtonian and visco-elastic fluids.

§ The temperature and concentration fields are not significantly affected by the visco-elasticity.

6. REFERENCES:

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[6] Erickson L.E., Fan L.T. and Fox V.G., (1966). Heat and mass transfer on a moving continuous flat plate with suction or injection. Industrial & Engineering Chemistry Fundamentals, 5(1), 19-25.

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Received on 11.01.2014 Accepted on 29.01.2014

Int. J. Tech. 4(1): Jan.-June. 2014; Page 42-46