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Soret and Dufour effects on MHD micropolar fluid flow over a linearly stretching sheet, through a non-Darcy porous medium

Reddy G. V. R., Krishna Y. H.

International Journal of Applied Mechanics and Engineering

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2018

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Vol. 23, no. 2

485--502

EN

In this paper, we discuss the Soret and Dufour effects on an MHD micropolar fluid flow over a linearly stretching sheet, through a non-Darcy porous medium, where stretching velocity of the sheet varies linearly with distance from the origin, and, temperature and concentration vary non-linearly in the boundary layer region. By suitable similarity transformations, the governing boundary layer equations are transformed to ordinary differential equations. These equations are solved by numerical computations with bvp4c along with the shooting technique method. The effects of the magnetic parameter, Soret number and Dufour number on velocity profiles, microrotation profile, heat transfer, and concentration, skin-friction, Nusselt number and Sherwood number are computed, discussed and analysed numerically and presented through tables and graphs.

2

Heat transfer in a liquid film over an unsteady stretching surface with the effects of viscous dissipation, thermal radiation and non-uniform heat source in the presence of external magnetic field

Abel. M. S., Tawade J. V.

International Journal of Applied Mechanics and Engineering

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2010

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Vol. 15, no 4

967-992

EN

This paper presents a mathematical analysis of an MHD flow and heat transfer to a laminar liquid film from a horizontal stretching surface. The flow of a thin fluid film and subsequent heat transfer from the stretching surface is investigated with the aid of similarity transformation. The transformation renders it possible to reduce the unsteady boundary layer equations to a system of non-linear ordinary differential equations. A numerical solution of the resulting nonlinear differential equations which agrees well with the analytic solution, is obtained by the efficient shooting technique. The effects of boundary layer thickness on various physical parameters such as the unsteadiness parameter S and magnetic parameter Mn, Prandtl number Pr, Eckert number Ec, thermal radiation parameter Nr and non-uniform heat source/sink parameters which determine the temperature profiles, the heat transfer coefficient are tabulated and plotted in figures. It is shown that the heat fluxes from the liquid to the elastic sheet decreases with S for […] and increases with S for […]. Some important findings reported in this work reveal that the combined effect of thermal radiation and non-uniform heat source have significant impact on controlling the rate of heat transfer in the boundary layer region.

3

Hall and ion-slip effects on the flow of micropolar fluid between parallel plates

Srinivasacharya D., Shiferaw M.

International Journal of Applied Mechanics and Engineering

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2008

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Vol. 13, no 1

251-262

EN

The steady flow of an incompressible and electrically conducting micropolar fluid between two parallel infinite plates is studied taking Hall and ionic effects into consideration. The fluid motion is due to the constant pressure gradient. An extemal uniform magnetic field directed perpendicular to the flow direction is applied. The expressions for the velocity and micro rotation are obtained. The effects of micropolar parameters, magnetic parameter, Hall parameter and ion slip parameter on the velocity, and micro rotation are discussed.

4

Diffusion of chemically reactive species of an electrically conducting visco-elastic fluid immersed in a porous medium over a stretching sheet with prescribed surface concentration and prescribed wall mass flux

Rajagopal K., Veena P. H., Pravin V. K.

International Journal of Applied Mechanics and Engineering

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2008

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Vol. 13, no 2

457-472

EN

In this paper, we present a mathematical analysis of mass transfer phenomena in a magneto hydrodynamic visco-elastic fluid immersed in a porous medium with prescribed surface concentration and prescribed wall mass flux. The influence of reaction rate on the transfer of chemically reactive species is studied. The flow is caused solely by the linearly stretching sheet and the reactive species is emitted from this sheet and undergoes an isothermal and homogeneous one stage reaction as it diffuses into the surrounding fluid. Several non-dimensional similarity transformations are introduced to reduce the concentration conservation equation to an ordinary differential equation in both the cases. (PST and PHF). An exact analytical solution due to Siddappa and Abel (ZAMP 36, 1985) is adopted for velocity, whereas the concentration equation is solved analytically for first order reactions in both the PST and PHF cases. The computations showed that the effect of destructive chemical reaction is to reduce the thickness of the concentration boundary layer and increase the mass transfer rate from the sheet to the surrounding fluid in the presence of a transverse magnetic field. This effect is more effective for zero and first order reactions than for thesecond and higher order. The effect of various physical parameters are analysed in the PST and PHF cases. The effects of all these parameters on wall concentration gradient are also discussed.

5

Unsteady mass transfer and magnetohydrodynamic flow of visco-elastic fluid over a stretching sheet saturated in a porous medium with suction/blowing

Veena P. H., Pravin V. K., Nagbhooshan J. K.

International Journal of Applied Mechanics and Engineering

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2007

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Vol. 12, no 1

263-282

EN

An unsteady two-dimensional and mass transfer flow of a visco-elastic, incompressible and electrically conducting fluid saturated in a porous medium with suction or blowing is studied. The permeability of the porous medium fluctuates with time about a constant mean. The surface absorbs the fluid with constant velocity and the velocity oscillates depending on the stretching rate (b). Analytical solutions for the velocity, skin friction and concentration are obtained. The influence of various parameters entering into the problem are discussed. The velocity of the visco-elastic fluid is found to decrease in the presence of the magnetic field and porous media as compared to the study of viscous fluid. It is also found that the effect of unsteadiness in the wall velocity and skin friction are found to be appreciable.