Heat and mass transfer on MHD heat generating flow through a porous medium in a rotating fluid

The problem of the free-convection flow of a viscous heat generating fluid through porous media in a rotating frame of reference is considered for the case when a strong magnetic field is imposed in a direction which is perpendicular to the free-stream and makes an angle to the vertical direction. Analytical expressions for the velocity field and temperature are given, and the influences of the various parameters on the velocity field are discussed.     

Heat and mass transfer in rotating fluid with Hall current,I

Hall effects on the hydromagnetic free convection resulting from the combined effects of thermal and mass diffusion of an electrically conducting liquid past an infinite vertical porous plate in a rotating system have been analysed. The expressions for the mean velocity, mean temperature in the boundary layer and the mean skin friction, the mean rate of heat transfer on the plate are derived. The effects of magnetic parameterM, Hall parameterm, Schmidt number Sc, and Ekman numberE on the flow field, are discussed with the help of graphs and tables.     

Heat and mass transfer in rotating fluid with Hall current,II

Effects of Hall current on the hydromagnetic free-convection resulting from the combined effects of thermal and mass diffusion of an electrically conducting liquid past an infinite vertical porous plate in a rotating frame of reference have been analysed. As the mean steady flow has been presented in Part I, only the solutions for the transient primary and secondary velocity profiles, transient temperature profiles in the boundary layer and the transient skin friction, the transient rate of heat transfer on the plate are presented in this work. The influence of the different parameters entering into the problem are discussed.     

Free convection in hydromagnetic flows of a viscous heat-generating fluid with wall temperature oscillation and Hall currents

A study is made of the free convection in hydromagnetic flows through a porous medium of a heat generating fluid past an infinite vertical porous plate. A strong magnetic field is imposed in a direction which is perpendicular to the free stream and makes an alge to the vertical direction. The governing equations for the hydromagnetic fluid flow and the heat transfer are solved analytically. The influence of Hall currents, the permeabilityK and the inclination upon the velocity field are shown in figures.     

Heat and mass transfer of an oscillatory flow with Hall current

In the first part of these notes new expressions—simpler than any previously obtained—are presented in integral form for the derivatives of the α _n ⁰ -functions (required for an interpretation of the observed light changes of eclipsing variables) with respect to the fractional radiir _{1, 2} and projected separation δ of their centres in terms of the modified Bessel functionsK _{0, 1} (x) of the second kind; and utilized for establishing new asymptotic formulae for the computation of ‘boundary integrals’ of the formJ _?1 ⁰ ,n(μ). In the second part of this paper, by a resort to bi-polar coordinates, we shall establish a new type of expansions for the α _n ⁰ -functions valid for any type of eclipses, and converging faster than the expansions of the cross-correlation integral of the form (1) for α _n ⁰ that have so far been established.     

Hall effects on heat and mass transfer flow with variable suction and heat generation

A study of the combined buoyancy effects of thermal and mass diffusion on MHD convection flow in the presence of Hall currents with variable suction and heat generation has been carried out. Analytical expressions for the velocity and the temperature of the fluid are given. The effects of Hall currents, parameterm, and heat source parameter on the velocity are discussed.     

Heat and mass transfer of an oscillatory flow with Hall current,II

An analysis of Hall current on the combined effects of thermal and mass diffusion of an electrically conducting liquid past an infinite vertical porous plate is performed. Analytical expressions for the transient velocity, the transient temperature in the boundary layer and the skin-friction on the plate are derived. The effects of various parameters on the velocity, temperature, shearing stresses and rate of heat transfer are shown by graphs and tables.     

Hall effects on heat and mass transfer flow through porous medium

Effects of Hall current on free convection and mass transfer flow through a porous medium bounded by a vertical surface has been analysed. The problem is solved analytically. The velocity profiles are shown on graphs. Effects ofm (Hall parameter).K ^* (permeability parameter), and Sc (Schmidt number) on velocity are discussed.     

Some cylindrically-symmetric cosmological models in general relativity representing viscous fluid and perfect fluid with heat conduction

The paper considers inhomogeneous space-times admitting a two-parameter group of motions and satisfying Einstein's field equations for viscous fluid and perfect fluid with heat conduction. Some homogenous solutions representing viscous fluid have also been obtained for which the free-gravitational field is of the magnetic type. Various physical and kinematical properties have been discussed.     

Pulsated hydromagnetic flow with free-convection currents and mass transfer along a vertical infinite porous plate

The influence of free-convection currents and mass transfer in the case of laminar, non-steady boundary layer is studied here. The fluid is the air, considered incompressible and electrically conductive. The free-stream velocity oscillates about a mean value. A pulsated suction is also taken into account. A second meterial lies in small concentration in the fluid and absorbs part of the radiation. The influence of various parameters (G. M. etc.) on the flow is examined.     

Temperature distribution and heat loss from a heated accelerated sphere in a viscous incompressible fluid

The temperature distribution and the heat loss per unit area is studied when a heated sphere is set into accelerated motion. Within the boundary layer the temperature increases in the oncoming part of the fluid (incident fluid) and drops at the rear. The heat loss increases with the time of motion.     

Unsteady hydromagnetic free-convection flow with radiative heat transfer in a rotating fluid

We consider the buoyancy-induced flow of an electrically-conducting fluid with radiative heat transfer past a vertical flat plate of infinite length. We assume that the density obeys the simple Boussinesq equation of state while the viscosity and thermal conductivity vary with temperature, that is a compressible fluid. If the temperature of the plate is such that a time-dependent component is superimposed on a constant value, the problem is tackled by asymptotic approximation. The results are compared and contrasted with those of incompressible flow.     

Unsteady hydromagnetic free-convection flow with radiative heat transfer in a rotating fluid

We study the unsteady free-convection flow near a moving infinite flat plate in a totating medium by imposing a time-dependent perturbation on a constant plate temperature. The temperatures involved are assumed to be very large so that radiative heat transfer is significant, which renders the problem very nonlinear even on the assumption of a differential approximation for the radiative flux. When the perturbation is small, the transient flow is tackled by the Laplace transform technique. Complete first-order solutions are deduced for an impulsive motion.     

MHD free-convection and mass transfer flow through a porous medium with heat source

An analytical study is performed to examine the heat source characteristics on the free-convection and mass transfer flow past an impulsively started infinite non-conducting vertical plate of a viscous, incompressible electrically-conducting fluid under the action of a uniform magnetic field through porous medium. The effects of various parameters on the velocity field are extensively discussed.     

Unsteady free-convective flow and mass transfer in a rotating porous medium with Hall current,I

The Hall effect on the unsteady hydromagnetic free-convection resulting from the combined effects of thermal and mass diffusion of an electrical-conducting liquid through a porous medium past an infinite vertical porous plate in a rotating system have been analysed. The expressions for the mean velocity, mean skin friction, and mean rate of heat transfer on the plate are derived. The effects of magnetic parameterM, Hall parameterm, Ekman numberE, and permeability parameterK ^* on the flow field are discussed with the help of graphs and tables.Nomenclature C _p specific heat at constant pressure - C the species concentration inside the boundary layer - C _w the species concentration at porous plate - C the species concentration of the fluid at infinite - C dimensionless species concentration - D chemical molecular diffusivity - E Ekman number - Ec Eckert number - g acceleration due to gravity - Gr Grashof number - Gm modified Grashof number - H ₀ applied magnetic field - (J _x, J_y, J_z) components of current density - M magnetic parameter - m Hall parameter - P Prandtl number - q _m mean rate of heat transfer - Sc Schmidt number - t time - t dimensionless time - T temperature of fluid - T _w temperature of the plate - T temperature of fluid at infinite - T dimensionless temperature - (u, v, w) components of the velocityq - w ₀ suction velocity - (x, y, z) Cartesian coordinates - z dimensionless coordinate normal to the plate Greek symbols coefficient of volume expansion - * coefficient of thermal expansion with concentration - frequency - dimensionless frequency - k thermal conductivity - K ^* permeability parameter - dinematic viscosity - density of the fluid in the boundary layer - coefficient of viscosity - _e magnetic permeability - angular velocity - electrical conductivity of the fluid - _m mean skin friction - _mn mean skin friction in the direction ofx - _mv mean skin friction in the direction ofy     

Cylindrically symmetric and inhomogeneous cosmological models with viscous fluid,heat flux and electromagnetic field

In this paper cylindrically symmetric, inhomogeneous cosmological models with heat flux, viscous fluid and electromagnetic field are obtained. Various physical and geometrical properties of the models are also discussed.     

Effects of mass transfer,free-convection currents and heat sources on the Stokes' problem for an infinite vertical plate

An exact analysis of the effects of heat sources, mass transfer and free-convection currents on the flow past an impulsively started vertical plate is investigated. Closed-form solutions to the velocity and temperature field have been derived by using Laplace transform and expressions are given for the Skin-friction and the rate of heat transfer. Variations of the above quantities are presented graphically, and the paper is concluded with a quantitative discussion.     

Thermal-convective instability of a composite plasma in a stellar atmosphere with Hall currents

The problem of thermal-convective instability of a hydromagnetic composite plasma in a stellar atmosphere has been studied with Hall effects. The criterion for monotonic instability has been found to be unchanged by the presence of Hall effects.     

Effects of free convection currents and mass transfer on flow past a vertical oscillating plate

An exact analysis of the flow caused by an oscillating vertical plate in the presence of free-convection currents and foreign mass has been presented. Solutions have been derived by Laplace-transform technique. Velocity profiles and leading edge effects have been shown for different gases present in air. During the course of discussion, the effects of Gr (Grashof number), Gm (modified Grashof number), Sc (Schmidt number), on the flow have been discussed. It has been observed that at all small values of Sc, transition from conduction to convection exists but at large values of Sc, such a transition is not present.     

Heat and mass transfer in convective flow of an incompressible rarefied visco-elastic fluid in presence of transverse magnetic field

Analytical study is performed to examine heat and mass transfer characteristics of natural convection flow of an incompressible, rarefied visco-elastic fluid past an infinite vertical porous plate with constant suction in the presence of transverse magnetic field under combined buoyancy force effects of thermal and mass diffusion. The effects of various parameters on mean velocity and mean skin-friction are shown graphically followed by a comparative study of Newtonian and non-Newtonian (visco-elastic). rarefied states.