scholarly journals Aligned Magnetic Field, Radiation, and Rotation Effects on Unsteady Hydromagnetic Free Convection Flow Past an Impulsively Moving Vertical Plate in a Porous Medium

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Sandeep Naramgari ◽  
Sugunamma Vangala ◽  
Mohankrishna Penem

We analyse the effects of aligned magnetic field, radiation, and rotation on unsteady hydromagnetic free convection flow of a viscous incompressible electrically conducting fluid past an impulsively moving vertical plate in a porous medium in presence of heat source. An exact solution of the governing equations in dimensionless form is obtained by Laplace transform technique in ramped temperature case. To compare the results obtained in this case with that of isothermal plate, the exact solution of the governing equations is also obtained for isothermal plate and results are discussed graphically in both ramped temperature and isothermal cases.

2013 ◽  
Vol 62 (3) ◽  
Author(s):  
Muhamad Najib Zakaria ◽  
Abid Hussanan ◽  
Ilyas Khan ◽  
Sharidan Shafie

The present paper is on study of the influence of radiation on unsteady free convection flow of Brinkman type fluid near a vertical plate containing a ramped temperature profile. Using the appropriate variables, the basic governing equations are reduced to nondimensional equations valid with the imposed initial and boundary conditions. The exact solutions are obtained by using Laplace transform technique. The influence of radiation near a ramped temperature plate is also compared with the flow near a plate with constant temperature. The numerical computations are carried out for various values of the physical parameters such as velocity, temperature, skin friction and Nusselt number and presented graphically.


Author(s):  
Nor Athirah Mohd Zin ◽  
Ahmad Qushairi Mohamad ◽  
Ilyas Khan ◽  
Sharidan Shafie

The unsteady magnetohydrodynamic (MHD) free convection flow of Jeffrey fluid embedded in porous medium past an oscillating vertical plate generated by thermal radiation with ramped wall temperature is investigated. The incompressible fluid is taken electrically conducting under the action of transverse magnetic field towards the flow. Constitutive relation of Jeffrey fluid is employed to model the governing equations in terms of partial differential equations with some physical conditions. The transformed dimensionless governing equations are solved analytically using Laplace transform technique. The impact of various pertinent parameters namely material parameter of Jeffrey fluid , dimensionless parameter of Jeffrey fluid , phase angle , Hartmann number , permeability parameter , Grashof number , Prandtl number , radiation parameter  and dimensionless time  on velocity and temperature distributions are presented graphically and discussed in details. It is observed that, the permeability parameter tend to retard the fluid velocity for ramped wall temperature but enhance the velocity for an isothermal plate. Besides that, this study shows, the amplitude of velocity and temperature fields for ramped wall temperature are always lower than isothermal plate. A comparison with the existing published work is also provided to confirm the validity of the present results and an excellent agreement are found. 


2009 ◽  
Vol 14 (1) ◽  
pp. 73-84 ◽  
Author(s):  
G. Palani ◽  
I. A. Abbas

This paper investigates the combined effects of magnetohydrodynamics and radiation on free convection flow past an impulsively started isothermal vertical plate with Rosseland diffusion approximation. The fluid considered is a gray, absorbingemitting radiation but a non-scattering medium, with approximate transformations the boundary layer governing the flow are reduced to non-dimensional equations valid in the free convection regime. The dimensionless governing equations are solved by the finite element method.


2013 ◽  
Vol 465-466 ◽  
pp. 149-154
Author(s):  
Marneni Narahari ◽  
Sowmya Tippa ◽  
Rajashekhar Pendyala

Theoretical analysis of unsteady magnetohydrodynamic free convection flow of a viscous incompressible radiative fluid past an infinite vertical plate with constant heat and mass flux is presented. The dimensionless governing linear partial differential equations have been solved using the Laplace transform technique. The exact solutions for the velocity, temperature and concentration fields are derived. The effects of radiation, magnetic field and buoyancy ratio parameters on the velocity and temperature fields are discussed through graphs. It is found that the velocity increases with increasing radiation parameter whereas it decreases with increasing magnetic field parameter for buoyancy assisted flows.


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