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Mixed Convection on a Vertical Flat Plate with Variable Magnetic Field

Dimian M. F., Hadhoda M. Kh.

Mechanics and Mechanical Engineering

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2007

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Vol. 11, nr 1

97-112

EN

The steady laminar incompressible boundary layer mixed convection flow of an electrically conducting fluid on a vertical flat plate in the presence of an applied magnetic field has been studied. The effect of the induced magnetic field has been considered in the analysis. The resulting partial differential equations are transformed into a system of ordinary differential equations which have been solved numerically using shooting method. Two cases are considered here for the buoyancy force: (i) when it acts in the same direction as the forced flow (Tw > T∞), (ii) when it acts in the opposite direction to the forced flow (Tw < T∞). The velocity profiles, temperature profiles, the skin friction on the plate and the rate of heat transfer coeffcient (Nusselt number) are computed and discussed for different values of the magnetic force number β, the thermal buoyancy force ╏, reciprocal of the magnetic Prandtl number α and viscous dissipation parameter (Eckert number) Ec for the two cases.

2

Mixed Convection on a Vertical Flat Plate with Variable Magnetic Field

Dimian M. F., Hadhoda M. Kh.

Mechanics and Mechanical Engineering

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2005

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Vol. 9, nr 2

15--28

EN

The steady laminar incompressible boundary layer mixed convection flow of an electrically conducting fluid on a vertical flat plate in the presence of an applied magnetic field has been studied. The effect of the induced magnetic field has been considered in the analysis. The resulting partial differential equations are transformed into a system of ordinary differential equations which have been solved numerically using shooting method. Two cases are considered here for the buoyancy force: (i) when it acts in the same direction as the forced flow (Tω > T∞), (ii) when it acts in the opposite direction to the forced flow (Tω < T∞). The velocity profiles, temperature profiles, the skin friction on the plate and the rate of heat transfer coefficient (Nusselt number) are computed and discussed for different values of the magnetic force number β, the thermal buoyancy force ╏, reciprocal of the magnetic Prandtl number a and viscous dissipation parameter (Eckert number) Ec for the two cases.

3

Natural convection flows with variable viscosity, heat and mass diffusion along a vertical plate

Dimian M. F., Hadhoda M. K.

Mechanics and Mechanical Engineering

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2004

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Vol. 7, nr 2

61-76

EN

The aim of this paper is a numerical study of laminar double diffusive free convection viscous flows adjacent to a vertical plate, taking into account the variation of the viscosity and double-diffusive heat and mass transfer with temperature. The governing conservation equations of mass, momentum, energy and chemical species are non-dimensionalized by using appropriate transformations. The resulting equations are solved numerically by using the fourth order Runge-Kutta integration scheme along with the Nachtsheim-Swiger shooting technique. It is noticed that both the velocity and concentration of air are increasing as the parameter Β 2, (the species diffusion parameter) increases, but an opposite effect for the velocity is observed at a certain distance far from the plate. It is also observed that the temperature decreases as the parameter Β 2 increases. The shearing stress at the plate, the local Nusselt number and the local Sherwood number are obtained. The friction coefficient at the plate, of heat and mass transfer at the plate, the momentum, thermal and concentration boundary layers thickness (δ, δ T, δ C) have been estimated for different values of α, Sc and N.

4

Effect of the magnetic field on forced convection flow along a wedge with variable viscosity

Dimian M. F.

Mechanics and Mechanical Engineering

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2004

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Vol. 7, nr 1

107-117

EN

This paper presents a study of the flow of a viscous incompressible fluid along a heated wedge, taking into account the variation of the viscosity with temperature. The flow is under the influence of a magnetic field B(x) along y direction applied perpendicular to the surface of the boundary layer along x direction and an electric field E(x) along z direction. The boundary layer equations are transformed to nonlinear ordinary differential equations and are solved numerically. The effects of the magnetic field on the velocity and the temperature and the shear stress on the surface (Tw) are studied. It is found that the velocity of the fluid increases with increasing the magnetic field parameter M, with the other parameters kept constant. It is also established that the temperature of the wedge decreases with increasing M value. The value of the skin friction increases whereas the rate of heat transfer decreases owing to increasing the magnetic field parameter and also according to decreasing the viscosity.