Hydromagnetic Free Convection Research Articles

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

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

Unsteady hydromagnetic free-convection flow with radiative heat transfer in a rotating fluid of arbitrary optical thickness, III

This paper investigates transient effects on the flow of a thermally-radiating and electrically-conducting compressible gas in a rotating medium bounded by a vertical flat plate. The transience is provoked by a time-dependent perturbation on a constant plate temperature. The problem particularly focusses on an optically thick gas and a gas of arbitrary optical thickness when the difference between the wall and free-stream temperatures is small. Analytical results are possible only for limiting values of time and these results are discussed quatitatively. Indeed the assumption of small temperature difference is more appropriate for plates which are opaque than transparent.

Finite difference analysis of unsteady hydromagnetic free-convection flow with constant heat flux

A numerical solution for unsteady hydromagnetic free-convection currents of a viscous incompressible and electrically conducting fluid induced by a vertical moving infinite plate is considered for constant heat flux at the plate. Velocity and skin-friction have been worked out for various values of the parameters occuring into the problem. It is found that magnetic parameter has a retarding effect on the velocity of air and water, while skin-friction increases with it.

A numerical study of the unsteady MHD free convection with hall current

Effect of Hall current on the hydromagnetic free-convection flow of an electrically-conducting viscous incompressible fluid past an impulsively accelerated vertical porous plate in the presence of a uniform transverse magnetic field subjected to a constant transpiration velocity is analyzed for the case of small magnetic Reynolds number. Numberical solutions are obtained for the axial and transverse components of the velocity as well as the skin-friction by employing the Crank-Nicolson implicit finite-difference method for all probable values of the Prandtl number. The results are discussed with the effects of the Grashof number Gr, the transpiration velocity parameter λ, the Hall current parameterm, and the magnetic field parameterM for the Prandtl number Pr=0.71 which represents air at 20° C.

Hall Effects on Hydromagnetic Free Convection Flow Along a Porous Flat Plate with Mass Transfer

Hall Effects on Hydromagnetic Free Convection Flow Along a Porous Flat Plate with Mass Transfer

Effect of Hall Current on Unsteady Hydromagnetic Free Convection Flow near an Infinite Vertical Porous Plate

La plaque poreuse est soumise a une vitesse d'aspiration/injection inversement proportionnelle a la racine carree du temps en presence d'un champ magnetique constant

Hydromagnetic free convection and mass transfer flow of non-Newtonian fluid through a porous medium bounded by an infinite vertical limiting surface with constant suction

An analysis of a two-dimensional steady-free convection and mass transfer flow of an incompressible, viscous, and electrically conductive non-Newtonian fluid through a porous medium bounded by a vertical infinite limiting surface (plane wall) has been presented in the presence of a transverse magnetic field. Approximate solutions to the coupled nonlinear equations governing the flow are derived and expression for the velocity, temperature, concentration, the rate of heat transfer, and the skin-friction are derived. Effects of Gr (Grashof number), Gm (modified Grashof number),M* (non-Newtonian parameter),N (magnetic parameter), and permeabilityK of the porous medium on the velocity, the skin-friction and the rate of heat transfer are discussed when the surface is subjected to a constant suction velocity.

Unsteady hydromagnetic free convection flow past an accelerated infinite vertical porous plate

Unsteady laminar free convection flow of a viscous incompressible and electrically conducting fluid past an accelerated vertical infinite porous plate subjected to a suction velocity proportional to (time)−1/2 is studied in presence of a uniform horizontal magnetic field. Results are discussed with the effects of the Grashof number Gr, and the magnetic field parameterM for Pr (the Prandtl number)=0.71 and 7.0 representing air and water respectively at 20 °C.

Hydromagnetic free-convection flow past an impulsively started vertical plate in a rotating fluid

The three dimensional flow of a viscous incompressible and electrically conducting fluid past an infinite vertical plate started impulsively in its own plane is discussed in a rotating system. The magnetic Reynolds number is taken small so that the induced magnetic field can be neglected. An exact solution is obtained for the axial and the transverse components of the velocity and the skin-friction by defining a complex velocity. It is observed that both velocity components of water (primary and secondary) decrease with rotation parameter in both cases, cooling and heating of the plate.

Effects of hall current on the hydromagnetic free convection with mass transfer in a rotating fluid

An exact analysis of Hall current on hydromagnetic free convection with mass transfer in a conducting liquid past an infinite vertical porous plate in a rotating fluid has been presented. Exact solution for the velocity field has been obtained and the effects ofm (Hall parameter),E (Ekman number), andS c (Schmidt number) on the velocity field have been discussed.

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.

Oscillatory hydromagnetic free-convection flow in the stokes problem past an infinite vertical porous plate in a rotating system, I

Rotation effect on the hydromagnetic free-convection flow of an electrically conducting, viscous, and incompressible fluid past a steadily moving vertical porous plate has been analysed in the presence of a transverse magnetic field. The free-stream velocity oscillates in time about a constant mean, while the suction velocity, normal to the porous plate, is constant. The magnetic Reynolds number of the flow is taken small enough so that the induced magnetic field can be neglected. The plate temperature is constant and the difference between the temperature of the plate and the free stream is moderately large causing the free-convection currents. The flow field is described by nonlinar coupled system of equations. With viscous dissipative heat taken into account, approximate solutions of the problem are obtained for the components of velocity field and temperature field as well as for the skin-friction components and rate of heat transfer.

Hydromagnetic free-convection flow near a time-varying accelerated vertical plate

The effect of a uniform transverse magnetic field on the free-convection flow of an electrically conducting fluid past an exponentially accelerated infinite vertical plate is analysed for both cases, when the magnetic lines of force are fixed relative to the fluid and the plate, respectively. The Laplace transform method is used to obtain the expressions for velocity and skin-friction. The effect of a magnetic parameter is to decrease the velocity of water when the magnetic field is fixed to the fluid, while it increases the velocity field when the magnetic lines of force are fixed relative to the plate.

Hall effects on MHD free-convection flow past an accelerated vertical porous plate

The effect of Hall currents on the hydromagnetic free-convection flow of an electrically conducting and incompressible viscous fluid past a uniformly accelerated infinite vertical porous plate is discussed. The magnetic Reynolds number is assumed to be small so that the induced magnetic field can be neglected. The governing equations of the flow are solved by defining a complex velocity with the help of the Laplace transform method when the Prandtl number is equal to unity. The influence of the various parameters on the unsteady flow field is presented for both the cases, cooling and heating of the porous plate by free-convection currents.

Hall effects on an oscillatory MHD flow in the Stokes problem past an infinite vertical porous plate, I

Hall effects on the hydromagnetic free convection flow of an electrically conducting incompressible viscous fluid past a steadily moving vertical porous plate has been analysed when the free stream oscillates in magnitude. The flow is subjected to a constant suction, through the porous plate, and the difference between wall temperature and the free-stream is moderately large causing the free convection currents. The mathematical analysis is presented for the hydromagnetic boundary layer flow without taking into account the induced magnetic field. This is a valid assumption for small magnetic Reynolds number. Approximate solutions for the components of velocity field and temperature field and their related quantities are obtained. The influence of various parameters entering into the problem is extensively discussed with the help of graphs and tables.

Hydromagnetic free convection effects on the oscillatory flow of an electrically conducting rarefied gas past an infinite vertical porous plate

Unsteady two-dimensional free convection flow of an electrically conducting, viscous, incompressible rarefied gas, past an infinite vertical porous plate in the presence of a transverse magnetic field is studied. The freestream velocity oscillates in time about a constant mean, while the suction velocity, normal to the porous plate, is constant. The magnetic Reynolds number of the flow is not taken to be small enough, so that the induced magnetic field is not negligible. The plate temperature is constant and the difference between the temperature of the plate and the freestream is moderately large causing the free convection currents. The flow field is described by a nonlinear coupled system of equations subjected to the first-order velocity slip and temperature jump boundary conditions. With viscous dissipative heat and Joule heating taken into account, approximate solutions of the problem are obtained for the velocity, temperature and induced magnetic field, as well as, for the related to them quantities of the skin friction, rate of the heat transfer and electric current density.

Hydromagnetic free convection flow through a porous medium between two parallel plates

Steady hydromagnetic free convective flow of a conducting fluid through a porous medium bounded by two parallel plates is considered and effects of G (Grashof number) and the K (permeability parameter) on the velocity field are discussed.

Hydromagnetic free convection flow past a vertical infinite porous plate in a rotating fluid

An exact analysis of free convection flow of an electrically conducting incompressible and viscous fluid past a vertical infinite porous plate under the action of a transverse magnetic field in a rotating fluid is presented. The plate and the fluid are assumed to rotate in a solid body rotation in a steady state. Exact solutions for the velocity and temperature field have been derived. The effects ofM (Hartmann number) on the flow characteristics are discussed.

Hydromagnetic free convection flow past an accelerated vertical infinite plate with variable suction and heat flux

This paper provides an analysis of the effects of a uniform transverse magnetic field on the free-convection flow of a viscous incompressible and electrically conductive fluid past an accelerated vertical infinite plate with variable suction or injection and heat flux. The magnetic Reynolds number is assumed small so that the induced magnetic field is considered negligible. Solutions of the equations governing the flow are obtained with the help of the power series when the prandtl number P is equal to one. Expressions are given for the velocity field, the temperature field and the skin-friction. The results obtained are discussed quantitatively in the last section of this paper.

Hydromagnetic free convection heat transfer of a viscous incompressible electrically conducting heat generating fluid‐flow past a vertical porous plate in the presence of free‐stream oscillations. I

Abstract Unsteady hydromagnetic boundary layer flow past a non‐conducting infinite vertical porous plate in presence of a transverse magnetic field is considered, taking into account the effect of the heat sources on the free convection‐flow and heat transfer of a viscous incompressible and electrically conducting fluid. The flow is subjected to a constant suction through the porous plate, and the difference between the plate temperature and the free stream is taken greater, equal or less than zero. The free stream oscillates in time about a constant mean value and the magnetic Reynolds number is taken to be small enough so that the induced magnetic field is negligible. Analytical expressions for the mean velocity, the mean temperature and their related quantities are obtained. The influence of the various dimensionless parameters entering into the problem is extensively discussed. A comparative study with the hydrodynamic case is also made whenever necessary.