On steady hydromagnetic flow of a radiating viscous fluid through a horizontal channel in a porous medium (original) (raw)
Transactions of FAMENA
This paper investigates the unsteady flow and heat transfer of a viscous, incompressible, and electrically conducting fluid through a porous medium in a horizontal channel. The basic physical properties of the fluid and the porous medium are constant. The fluids considered are those with the Prandtl number less than 1. The channel walls are made of horizontal permeable plates, which are at constant but different temperatures. Fluid suction/injection through the plates occurs at a velocity perpendicular to the plates, whose intensity is a cosine function of time. The applied external magnetic field is homogeneous and inclined in relation to the transverse plane of the channel. The problem is dealt with through an inductionless approximation. Fluid flow is instigated by constant pressure drops along the channel. The equations used to describe the problem are transformed to dimensionless forms and solved analytically using the perturbation method. Approximate analytical expressions for dimensionless fluid flow velocity and dimensionless temperature are determined as functions of the following physical parameters: Prandtl number, Hartmann number, porosity factor, frequency, amplitude, and magnetic field inclination angle. Numerical results are presented as diagrams and tables and are used to analyse the influence of physical parameters on the fluid flow velocity and temperature.
International Communications in Heat and Mass Transfer, 2000
The effect of variable viscosity and magnetic field on the flow and heat transfer past a continuously moving porous plate in a stationary fluid taking into account the radiation effect has been analyzed. The fluid viscosity is assumed to vary as an inverse linear function of temperature. By means of the similarity solutions, deviation of the velocity and temperature fields as well as the skin friction and heat transfer results from their constant values are determined numerically by using the shooting method. The effects of variable viscosity, radiat~n, magnetic and suction (or injection) parameters on the velocity and temperature profiles have been studied.
Journal of Porous Media, 2007
The effect of thermal radiation on free convection flow with variable viscosity and uniform suction velocity along a uniformly heated vertical porous plate embedded in a porous medium in the presence of a uniform transverse magnetic field is analyzed. The viscosity of the fluid is taken as a function of temperature. The effect of internal heat generation/absorption is also considered. The Rosseland diffusion approximation is used to describe the radiative heat flux in the energy equation. The governing equations are solved using the local nonsimilarity method. Numerical results for the transient velocity, the temperature, the local and average skin friction, and the rate of heat are shown in graphic and tabulated forms.
We discuss the effect of radiation on unsteady MHD free connective flow through a porous medium in a vertical channel .The unsteadiness in the flow is due to the traveling thermal wave imposed on the wall y = L . A uniform magnetic field of strength Ho is applied normal to the boundaries. The coupled equations governing the flow and heat transfer have been solved by using a perturbation technique with the aspect ratio as perturbation parameter. The expression for the velocity, the temperature, the shear stress and the rate of heat transfer are derived and are analysed for different variations of the governing parameters G,R,M, and
International Journal of Mathematical Archive, 2012
T he aim of this paper is to study an unsteady free convection unsteady flow of a viscous incompressible, electrically conducting, rotating liquid in a porous medium past an infinite isothermal vertical plate with constant heat source / sink in the presence of a uniform magnetic field applied perpendicular to the flow region. Expressions for primary and secondary velocities and temperature distribution are obtained by solve the governing equations using perturbation technique. The expressions for the skin-friction coefficient and rate of heat transfer are also derived. The effects on Prandtl Number (Pr), Grashof Number (Gr), Rotation Parameter (E), Heat Sources/ Sink Parameter (a 0 ), Magnetic Parameter (M) and Permeability (K 0 ) obtained on the above flow quantities are studied through graphs and tables.
Hydromagnetic Oscillatory Convective Flow through Porous Medium in a Rotating
tical analysis of a hydromagnetic oscillatory free convection flow of an electrically conducting viscous incompressible radiating fluid in a vertical porous channel filled with porous medium is analyzed. The parallel porous plates are subjected to a constant injection and suction velocity and a magnetic field of uniform strength is applied perpendicular to the plates of the channel. The magnetic Reynolds number is assumed to be very small so that the induced magnetic field is negligible. The entire system rotates about an axis perpendicular to planes of the plates. The temperature difference between the plates is high enough to induce the heat due to radiation. An exact solution of the purely oscillatory flow is obtained. The velocity and the skin-friction and Nusselt number for the rate of heat transfer in terms of their amplitude and phase angle have been shown graphically to observe the effects of rotation parameter Ω, porosity parameter K, magnetic body force M, Radiation parameter N and the frequency of oscillation 𝜔. Applications of the model include fundamental magneto-fluid dynamics,
International Journal of …, 2012
The aim of this paper is to study an unsteady free convection unsteady flow of a viscous incompressible, electrically conducting, rotating liquid in a porous medium past an infinite isothermal vertical plate with constant heat source / sink in the presence of a uniform magnetic field applied perpendicular to the flow region. Expressions for primary and secondary velocities and temperature distribution are obtained by solve the governing equations using perturbation technique. The expressions for the skin-friction coefficient and rate of heat transfer are also derived. The effects on Prandtl Number (Pr), Grashof Number (Gr), Rotation Parameter (E), Heat Sources/ Sink Parameter (a 0 ), Magnetic Parameter (M) and Permeability (K 0 ) obtained on the above flow quantities are studied through graphs and tables.
2010
This paper investigates effects of thermal radiation and magnetic field on hydromagnetic Couette flow of a highly viscous fluid with temperature-dependent viscosity and thermal conductivity at constant pressure through a porous channel. The influence of the channel permeability is also assessed. The relevant governing partial differential equations have been transformed to non-linear coupled ordinary differential equations by virtue of the steady nature of the flow and are solved numerically using a marching finite difference scheme to give approximate solutions for the velocity and temperature profiles. We highlight the effects of Nahme numbers, magnetic field, radiation and permeability parameters on both profiles. The results obtained are used to give graphical illustrations of the distribution of the flow variables and are discussed.
International Journal of Apllied Mathematics, 2020
A study for the problem of unsteady convection flow of a viscous incompressible electrically conducting micro-polar fluid in a porous medium past an inclined moving porous plate in the presence of a transverse magnetic field, heat generation, radiation absorption, chemical reaction and suction is presented. The porous plate moves with a constant velocity and the stream velocity is assumed to follow an exponentially increasing perturbation law. The porous plate absorbs the polar fluid with a suction velocity which varies with time. The dimensionless governing equations are solved analytically by perturbation technique. The numerical results are also compared with corresponding Newtonian fluid flow problems. The effects of various parameters on the velocity, micro-rotation, temperature, concentration fields, skin friction coefficient, couple stress coefficient, Nusselt number and Sherwood number are presented in graphical and tabular form.