scholarly journals Radiation and mass transfer effects on MHD free convection flow past a moving vertical cylinder in a porous medium

2011 ◽  
Vol 7 (1) ◽  
pp. 1-10 ◽  
Author(s):  
S. Suneetha ◽  
N. Bhaskar Reddy
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Free Convection ◽  
Vertical Cylinder ◽  
Mhd Flow ◽  
Convection Flow ◽  
Physical Parameters ◽  
Radiation Parameter ◽  
Grashof Number ◽  
Flow Past

The interaction of free convection with thermal radiation of a viscous incompressible unsteady MHD flow past a moving vertical cylinder with heat and mass transfer in a porous medium is analyzed. The fluid is a gray, absorbing-emitting but non-scattering medium and the Rosseland approximation is used to describe the radiative heat flux in the energy equation. The governing equations are solved by using an implicit finite-difference scheme of Crank-Nicolson type. The effects of various physical parameters such as thermal Grashof number, mass Grashof number, magnetic parameter, radiation parameter and Schmidt number on the velocity, temperature,  concentration,  local as well as average skin-friction, Nusselt number and Sherwood number for various parameters are computed and represented graphically. It is found that at small values of radiation parameter ,  the velocity and temperature of the fluid increases sharply near the cylinder as the time  increases. Also, an increase in the magnetic field leads to a decrease in the velocity and a rise in the temperature.As the permeability parameter increases,it is seen that the flow accelerates. This model finds applications in geophysics and engineering.DOI: 10.3329/jname.v7i1.2901

scholarly journals Radiation and mass transfer effects on unsteady MHD free convection flow of an incompressible viscous fluid past a moving vertical cylinder

2009 ◽  
Vol 36 (3) ◽  
pp. 239-260 ◽  
Author(s):  
Reddy Gnaneswara ◽  
Reddy Bhaskar
Keyword(s):  
Mass Transfer ◽  
Free Convection ◽  
Heat And Mass Transfer ◽  
Vertical Cylinder ◽  
Mhd Flow ◽  
Convection Flow ◽  
Radiation Parameter ◽  
Grashof Number ◽  
Implicit Finite Difference Scheme ◽  
Transient Velocity

The interaction of free convection with thermal radiation of a viscous incompressible unsteady MHD flow past a moving vertical cylinder with heat and mass transfer is analyzed. The fluid is a gray, absorbing-emitting but non-scattering medium and the Rosseland approximation is used to describe the radiative heat flux in the energy equation. The governing equations are solved using an implicit finite-difference scheme of Crank-Nicolson type. Numerical results for the transient velocity, the temperature, the concentration, the local as well as average skin-friction, the rate of heat and mass transfer for various parameters such as thermal Grashof number, mass Grashof number, magnetic parameter, radiation parameter and Schmidt number are shown graphically. It is observed that, when the radiation parameter increases the velocity and temperature decrease in the boundary layer. Also, it is found that as increase in the magnetic field leads to decrease in the velocity field and rise in the thermal boundary thickness.

Unsteady free convection flow past a periodically accelerated vertical plate with Newtonian heating

2016 ◽  
Vol 26 (7) ◽  
pp. 2119-2138 ◽  
Author(s):  
M.C. Raju ◽  
S.V.K. Varma ◽  
A.J. Chamkha
Keyword(s):  
Mass Transfer ◽  
Free Convection ◽  
Skin Friction ◽  
Heat And Mass Transfer ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Physical Parameters ◽  
Content Type ◽  
Flow Past ◽  
Laplace Transform Technique

Purpose The purpose of this paper is to present an analytical study for a problem of unsteady free convection boundary layer flow past a periodically accelerated vertical plate with Newtonian heating (NH). Design/methodology/approach The equations governing the flow are studied in the closed form by using the Laplace transform technique. The effects of various physical parameters are studied through graphs and the expressions for skin friction, Nusselt number and Sherwood number are also derived and discussed numerically. Findings It is observed that velocity, concentration and skin friction decrease with the increasing values of Sc whereas temperature distribution decreases in the increase in Pr in the presence of NH. Research limitations/implications This study is limited to a Newtonian fluid. This can be extended for non-Newtonian fluids. Practical implications Heat and mass transfer frequently occurs in chemically processed industries, distribution of temperature and moisture over agricultural fields, dispersion of fog and environment pollution and polymer production. Social implications Free convection flow of coupled heat and mass transfer occurs due to the temperature and concentration differences in the fluid as a result of driving forces. For example, in atmospheric flows, thermal convection resulting from heating of the earth by sunlight is affected differences in water vapor concentration. Originality/value The authors have studied heat and mass transfer effects on unsteady free convection boundary layer flow past a periodically accelerated vertical surface with NH, where the heat transfer rate from the bounding surface with a finite heat capacity is proportional to the local surface temperature, and which is usually termed as conjugate convective flow. The equations governing the flow are studied in the closed form by using the Laplace transform technique. The effects of various physical parameters are studied through graphs and the expression for skin friction also derived and discussed.

scholarly journals Heat and Mass Transfer of Unsteady Hydromagnetic Free Convection Flow Through Porous Medium Past a Vertical Plate with Uniform Surface Heat Flux

2017 ◽  
Vol 47 (3) ◽  
pp. 25-58 ◽  
Author(s):  
Mohamed Abd El-Aziz ◽  
Aishah S. Yahya
Keyword(s):  
Mass Transfer ◽  
Heat Flux ◽  
Porous Medium ◽  
Free Convection ◽  
Heat And Mass Transfer ◽  
Transport Model ◽  
Convection Flow ◽  
Physical Parameters ◽  
Free Convection Flow ◽  
Laplace Transform Technique

AbstractSimultaneous effects of thermal and concentration diffusions in unsteady magnetohydrodynamic free convection flow past a moving plate maintained at constant heat flux and embedded in a viscous fluid saturated porous medium is presented. The transport model employed includes the effects of thermal radiation, heat sink, Soret and chemical reaction. The fluid is considered as a gray absorbing-emitting but non-scattering medium and the Rosseland approximation in the energy equations is used to describe the radiative heat flux for optically thick fluid. The dimensionless coupled linear partial differential equations are solved by using Laplace transform technique. Numerical results for the velocity, temperature, concentration as well as the skin friction coefficient and the rates of heat and mass transfer are shown graphically for different values of physical parameters involved.

scholarly journals Transient radiative hydromagnetic free convection flow past an impulsively started vertical plate with uniform heat and mass flux

2006 ◽  
Vol 33 (1) ◽  
pp. 31-63 ◽  
Author(s):  
Ramachandra Prasad ◽  
Bhaskar Reddy ◽  
R. Muthucumaraswamy
Keyword(s):  
Free Convection ◽  
Mass Flux ◽  
Vertical Plate ◽  
Glass Production ◽  
Convection Flow ◽  
Radiation Parameter ◽  
Grashof Number ◽  
Coupled Equations ◽  
Flow Past ◽  
Uniform Heat

The interaction of free convection with thermal radiation of viscous incompressible MHD unsteady flow past an impulsively started vertical plate with uniform heat and mass flux is analyzed. This type of problem finds application in many technological and engineering fields such as rocket propulsion systems, space craft re-entry aerothermodynamics, cosmical flight aerodynamics, plasma physics, glass production and furnace engineering .The Rosseland approximation is used to describe the radiative heat transfer in the limit of the optically thin fluid. The non-linear, coupled equations are solved using an implicit finite difference scheme of Crank-Nicolson type. Velocity, temperature and concentration of the flow have been presented for various parameters such as thermal Grashof number, mass Grashof number, Prandtl number, Schmidt number, radiation parameter and magnetic parameter. The local and average skin friction, Nusslet number and Sherwood number are also presented graphically. It is observed that, when the radiation parameter increases the velocity and temperature decrease in the boundary layer. .

Soret Effect on Unsteady MHD Free Convection Flow Past an Impulsively Started Vertical Plate with Chemical Reaction

2018 ◽  
Vol 2 (01) ◽  
Author(s):  
N. K. Gupta ◽  
U. S. Rajput
Keyword(s):  
Magnetic Field ◽  
Free Convection ◽  
Chemical Reaction ◽  
Vertical Plate ◽  
Soret Effect ◽  
Mhd Flow ◽  
Convection Flow ◽  
Transform Method ◽  
Grashof Number ◽  
Flow Past

In this paper, we are analyzing Soret effect and inclined magnetic field on unsteady free convection MHD flow past an impulsively started vertical plate with chemical reaction. Fluid considered is electrically conducting. The Laplace transform method has been used to find the exact solutions for the concentration, momentum and energy equations. The flow model consists of a magnetic field inclined from vertical by an angle . The flow is considered unsteady and heat is transferred through free convection. The velocity profiles are discussed with the help of graphs drawn for different parameters like thermal Grashof number, the Soret number, the Prandtl number, the chemical reaction parameter, the Hartmann number, the Schmidt number, the mass Grashof number, time and inclination of magnetic field. The numerical values of skin friction have been discussed with the help of table for different parameters.

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