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Effect of Hall currents on unsteady magnetohydrodynamic two-ionized fluid flow and heat transfer in a channel

Raju T. Linga, Rao V. Gowrisankara

International Journal of Applied Mechanics and Engineering

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2021

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Vol. 26, no. 2

84--106

EN

An unsteady magnetohydrodynamic (MHD) heat transfer two-fluid flow of ionized gases through a horizontal channel between parallel non-conducting plates, by taking Hall currents into account is studied. The governing partial differential equations that describe the flow and heat transfer under the adopted conditions are solved for the velocity and temperature distributions by a regular perturbation technique. Profiles for the velocity and temperature distributions as well the rates of heat transfer coefficient are presented graphically, and a parametric study is performed. The results reveal that the combined effects of the Hartmann number, Hall parameter, and the ratios of viscosities, heights, electrical and thermal conductivities have a significant impact on an unsteady MHD heat transfer two-ionized fluid flow characteristics.

2

Thermal convection of magneto compressible couple-stress fluid saturated in a porous medium with Hall current

Mehta C. B., Singh M., Kumar S.

International Journal of Applied Mechanics and Engineering

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2016

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Vol. 21, no. 1

83--93

EN

An investigation is made on the effect of Hall currents on thermal instability of a compressible couple-stress fluid in the presence of a horizontal magnetic field saturated in a porous medium. The analysis is carried out within the framework of the linear stability theory and normal mode technique. A dispersion relation governing the effects of viscoelasticity, Hall currents, compressibility, magnetic field and porous medium is derived. For the stationary convection a couple-stress fluid behaves like an ordinary Newtonian fluid due to the vanishing of the viscoelastic parameter. Compressibility, the magnetic filed and couple-stress parameter have stabilizing effects on the system whereas Hall currents and medium permeability have a destabilizing effect on the system, but in the absence of Hall current couple-stress has a destabilizing effect on the system. It has been observed that oscillatory modes are introduced due to the presence of viscoelasticity, magnetic field porous medium and Hall currents which were non-existent in their absence.

3

Thermosolutal convection in Rivlin-Ericksen fluid in the presence of Hall currents in a porous medium in hydromagnetics

Kango S. K., Singh V.

International Journal of Applied Mechanics and Engineering

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2012

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Vol. 17, no. 1

71-82

EN

The thermosolutal instability of a layer of a Rivlin-Ericksen elastico-viscous fluid is considered in the presence of a uniform horizontal magnetic field to include the Hall currents in a porous medium. For the case of stationary convection, the Hall currents hasten the onset of convection, the magnetic field postpones the onset of convection, medium permeability also postpones the onset of convection in the presence of the Hall currents, whereas the kinematic viscoelasticity has no effect on the onset of convection. The Hall currents, kinematic viscoelasticity, magnetic field, medium permeability and the solute parameter introduce oscillatory modes in the system, which were non-existent in their absence. The case of overstability is also considered wherein the sufficient conditions for the non-existence of overstability are obtained.

4

Hall effect on thermal stability of ferromagnetic fluid in the presence of suspended particles

Aggarwal A. K., Makhija S.

International Journal of Applied Mechanics and Engineering

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2012

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Vol. 17, no. 2

349-365

EN

This paper deals with the theoretical investigation of the effect of Hall currents and suspended particles on the thermal stability of a ferromagnetic fluid heated from below. For a fluid layer between two free boundaries, an exact solution is obtained using a linearized stability theory and normal mode analysis. A dispersion relation governing the effects of suspended particles and Hall currents is derived. For the case of stationary convection, it is found that the magnetic field has a stabilizing effect, whereas the suspended particles and Hall currents are found to have a destabilizing effect on the system. The critical Rayleigh numbers and wave numbers of the associated disturbances for the onset of stability as stationary convection are obtained. The principle of exchange of stabilities is not valid for the problem under consideration, whereas in the absence of Hall currents (hence magnetic field), it is valid under certain conditions.