EFFECTS OF HALL CURRENT AND ROTATION ON UNSTEADY HYDROMAGNETIC COUETTE FLOW WITHIN A POROUS CHANNEL

2012 ◽  
Vol 04 (02) ◽  
pp. 1250015 ◽  
Author(s):  
G. S. SETH ◽  
J. K. SINGH ◽  
G. K. MAHATO
Keyword(s):  
Shear Stress ◽  
Couette Flow ◽  
Hall Current ◽  
Transverse Magnetic ◽  
Secondary Flows ◽  
Moving Plate ◽  
Electrically Conducting ◽  
Injection Parameter ◽  
Laplace Transform Technique ◽  
Current Parameter

Unsteady hydromagnetic Couette flow of a viscous, incompressible and electrically conducting fluid between two parallel porous plates taking Hall current into account in a rotating system is studied. Fluid flow within the channel is induced due to impulsive movement of the lower plate of the channel and is permeated by a uniform transverse magnetic field which is fixed relative to the moving plate. Solution of the governing equations is obtained by Laplace transform technique. The expression for the shear stress at the moving plate due to primary and secondary flows is also derived. Asymptotic behavior of the solution valid for small and large values of time t is analyzed to gain some physical insight into the flow pattern. Numerical values of primary and secondary velocities and that of shear stress at the moving plate due to primary and secondary flows are displayed graphically for various values of Hall current parameter m, rotation parameter K2, magnetic parameter M2, suction/injection parameter S and time t.

Magnetohydrodynamic Free Convective Couette Flow With Suction and Injection

2011 ◽  
Vol 133 (9) ◽  
Author(s):  
Basant K. Jha ◽  
Clement A. Apere
Keyword(s):  
Skin Friction ◽  
Couette Flow ◽  
Porous Plate ◽  
Moving Plate ◽  
Electrically Conducting ◽  
Flow Parameters ◽  
Riemann Sum ◽  
Injection Parameter ◽  
Laplace Transform Technique ◽  
The Time Domain

This paper considers the unsteady MHD free convective Couette flow of a viscous incompressible electrically conducting fluid between two parallel vertical porous plates. Both cases of the applied magnetic field being fixed either to the fluid or to the moving porous plate are considered. The solution of the governing equations has been obtained by using a Laplace transform technique. However, the Riemann-sum approximation method is used to invert the Laplace domain to the time domain. The unified solution obtained for the velocity have been used to compute the skin friction, while the temperature has been used to compute the Nusselt number. The effect of various flow parameters entering into the problem such as Prandtl number, Grashof number, and the suction/injection parameter are discussed with the aid of line graphs. The skin friction have been seen to decrease with both suction and injection on the surface of the moving plate when the channel is being cooled, while on the stationary plate, the magnitude of the skin friction increases with injection.

Hydromagnetic Flow Over a Conducting Thick Porous Plate With Hall Effects

1979 ◽  
Vol 46 (1) ◽  
pp. 220-223
Author(s):  
S. Chhatait ◽  
K. K. Mandal
Keyword(s):  
Magnetic Field ◽  
Hall Current ◽  
Porous Plate ◽  
Mhd Flow ◽  
Transverse Magnetic ◽  
Secondary Flows ◽  
Magnetic Field Effects ◽  
Induced Magnetic Field ◽  
Electrically Conducting ◽  
Wall Conductivity

MHD flow of an incompressible viscous electrically conducting fluid due to a uniform stream passing over a thick, porous conducting flat plate subjected to a uniform suction at the plate under the influence of uniform transverse magnetic field has been studied taking into account the effect of Hall current. Induced magnetic field has been taken into consideration and exact solutions have been obtained for primary and secondary flows and induced magnetic field. Effects of different parameters have been illustrated using graphs. It has also been pointed out that when the magnetic Prandtl number is very small effects of Hall current, wall conductivity, and thickness of the plate are all negligible.

scholarly journals Natural Convective Effects on MHD Boundary Layer Nanofluid Flow over an Exponentially Accelerating Vertical Plate

2021 ◽  
Vol 11 (6) ◽  
pp. 13790-13805
Keyword(s):  
Vertical Plate ◽  
Transverse Magnetic ◽  
Governing Equations ◽  
Nanofluid Flow ◽  
Moving Plate ◽  
Time Frequency ◽  
Laplace Transform Technique ◽  
Flow Transport ◽  
Mhd Boundary Layer ◽  
Radiation Heat Generation

The problem of unsteady natural convective nanofluid flow along with an exponentially accelerating vertical plate under the influence of transverse magnetic field is discussed in two important cases when the magnetic lines of force are fixed relative to the fluid or the moving plate. The governing equations are transformed into dimensionless form and tackled with the usual time-frequency Laplace transform technique. The impacts of various parameters on the heat transfer characteristics and nanofluid flow transport with thermal radiation, heat generation/absorption, and nanoparticle volume concentration have been studied through graphs.

scholarly journals Unsteady hydromagnetic couette flow due to ramped motion of one of the porous plates

2013 ◽  
Vol 18 (4) ◽  
pp. 1039-1056 ◽  
Author(s):  
B.K. Jha ◽  
H.M. Jibril
Keyword(s):  
Magnetic Field ◽  
Couette Flow ◽  
Porous Plate ◽  
Flow Region ◽  
Transverse Magnetic ◽  
Induced Magnetic Field ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Flow Formation ◽  
The Impact

Abstract An unsteady flow formation in Couette motion of an electrically conducting fluid subject to transverse magnetic field has been analyzed in the presence of suction/injection through the porous plates when one of the porous plates is in ramped motion. It is assumed that the porous plates are uniformly permeable and the fluid is entering the flow region through one of the porous plates at same rate as it is leaving through the other porous plate. The resulting boundary value problem has been solved exactly under the assumption of a negligible induced magnetic field, external electric field and pressure gradient. Unified closed form expressions for the velocity field and skin-friction corresponding to the case of a magnetic field fixed relative to the fluid or to the moving porous plate have been presented. In order to highlight the impact of the ramp motion of the porous plate on the fluid flow, it has also been compared with Couette flow between porous plates when one of the porous plates has been set into an impulsive motion.

scholarly journals Unsteady Magnetohydrodynamic Heat Transfer in a Semi-Infinite Porous Medium with Thermal Radiation Flux: Analytical and Numerical Study

2011 ◽  
Vol 2011 ◽  
pp. 1-17 ◽  
Author(s):  
O. Anwar Bég ◽  
J. Zueco ◽  
S. K. Ghosh ◽  
Alireza Heidari
Keyword(s):  
Shear Stress ◽  
Thermal Radiation ◽  
Numerical Study ◽  
Transverse Magnetic ◽  
Convection Flow ◽  
Time Interval ◽  
Short Time Interval ◽  
Plate Surface ◽  
Plate Temperature ◽  
Laplace Transform Technique

The unsteady, buoyancy-induced, hydromagnetic, thermal convection flow in a semi-infinite porous regime adjacent to an infinite hot vertical plate moving with constant velocity, is studied in the presence of significant thermal radiation. The momentum and energy conservation equations are normalized and then solved using both the Laplace transform technique and Network Numerical Simulation. Excellent agreement is obtained between both analytical and numerical methods. An increase in Hartmann number (M2) strongly decelerates the flow and for very high strength magnetic fields (M2=20), the flow is reversed after a short time interval. The classical velocity overshoot is also detected close to the plate surface for low to intermediate values of M2 at both small and large times; however this overshoot vanishes for larger strengths of the transverse magnetic field (M2=10). An increase in radiation-conduction parameter (Kr) significantly increases temperature throughout the porous regime at both small and larger times, adjacent to the plate, but decreases the shear stress magnitudes at the plate. Temperature gradient is reduced at the plate surface for all times, with a rise in radiation-conduction parameter (Kr). Shear stress is reduced considerably with an increase in Darcian drag parameter (Kp).

Unsteady MHD Flow of Radiating and Rotating Fluid with Hall Current and Thermal Diffusion Past a Moving Plate in a Porous Medium

2018 ◽  
Vol 389 ◽  
pp. 71-85
Author(s):  
Oluwole Daniel Makinde ◽  
Venkateswarlu Malapati ◽  
R.L. Monaledi
Keyword(s):  
Porous Medium ◽  
Hall Current ◽  
Chemical Species ◽  
Mhd Flow ◽  
Skin Friction Coefficient ◽  
Fluid Temperature ◽  
Species Concentration ◽  
Moving Plate ◽  
Laplace Transform Technique ◽  
Layer Flow

The paper examines the combined effects of Hall current, buoyancy forces, thermal radiation, thermo-diffusion and fluid rotation on an unsteady hydromagmetic boundary layer flow with heat and mass transfer over an impulsively moving vertical plate embedded in a porous medium. Base on some realistic simplified assumptions, the governing equations of momentum, energy and chemical species concentration are obtained and tackled analytically using Laplace transform technique. The numerical values of primary and secondary fluid velocities, fluid temperature and species concentration are displayed graphically while those of skin friction coefficient, Nusselt number and Sherwood number are presented in tabular form for different values of pertinent flow parameters.

Analysis of Radiative Magneto-Nanofluid over an Accelerated Plate in a Rotating Medium with Hall Effects

2017 ◽  
Vol 11 ◽  
pp. 129-145 ◽  
Author(s):  
Rohit Sharma ◽  
Syed Modassir Hussain ◽  
Hitesh Joshi ◽  
Gauri Shenkar Seth
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Shear Stress ◽  
Convective Flow ◽  
Research Work ◽  
Secondary Flows ◽  
Physical Parameters ◽  
Rotating Medium ◽  
Laplace Transform Technique ◽  
The Mathematical Model

Present research work has been undertaken to analyze the effects of Hall current on natural convective flow of radiative, incompressible, viscous and electrically conducting magneto-nanofluid over a uniformly accelerated moving vertical ramped temperature plate in a rotating medium. Three types of water based nanofluids containing the nanoparticles of alumina, copper and titanium oxide have been accounted. The mathematical model of the problem has been presented using the nanoparticle volume fraction model. The Laplace transform technique has been employed to solve the mathematical model. The closed-form expressions of nanofluid velocity, temperature, shear stress and rate of heat transfer at the plate have been obtained for both the conditions of ramped temperature and isothermal plates. The effects of various physical parameters on the nanofluid velocity due to primary and secondary flows and temperature have been exemplified using various graphs whereas, the numerical values of shear stress and rate of heat transfer at the plate have been reported in tabular form for different values of physical parameters of interest. Moreover, the numerical results have been compared for the natural convective flow near ramped temperature plate with the corresponding flow near isothermal plate. It has been noted that both the nanofluid velocity and temperature are higher in magnitude in the case of isothermal plate than that of ramped temperature plate. The results of present research work have been validated with the earlier published work.

Unsteady Hydromagnetic Flow Near a Moving Porous Plate

1981 ◽  
Vol 48 (2) ◽  
pp. 255-258 ◽  
Author(s):  
J. N. Tokis ◽  
G. C. Pande
Keyword(s):  
Porous Plate ◽  
Transverse Magnetic ◽  
Two Dimensional ◽  
Hydromagnetic Flow ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Magnetic Prandtl Number ◽  
Laplace Transform Technique ◽  
Infinite Extent ◽  
Two Dimensional Flow

Unsteady two-dimensional flow of a viscous incompressible and electrically conducting fluid near a moving porous plate of infinite extent in presence of a transverse magnetic field is investigated. Solution of the problem in closed form is obtained with the help of Laplace transform technique, when the plate is moving with a velocity which is an arbitrary function of time and the magnetic Prandtl number is unity. Three particular cases of physical interest are also discussed.

scholarly journals Hall-current effects on unsteady MHD flow between stretching sheet and an oscillating porous upper parallel plate with constant suction

2011 ◽  
Vol 15 (2) ◽  
pp. 527-536 ◽  
Author(s):  
Raju Changal ◽  
Reddy Ananda ◽  
Kumar Vijaya
Keyword(s):  
Stretching Sheet ◽  
Hall Current ◽  
Porous Plate ◽  
Fluid Motion ◽  
Mhd Flow ◽  
Transverse Magnetic ◽  
Physical Parameters ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Constant Suction

The unsteady MHD flow of an incompressible viscous electrically conducting fluid between two horizontal parallel non conducting plates, where the lower one is stretching sheet and the upper one is oscillating porous plate, is studied in the presence of a transverse magnetic field and the effects of Hall current. Fluid motion is caused by the stretching of the lower sheet and a constant suction is applied at the upper plate which is oscillating in its own plane. The stretching velocity of the sheet is assumed to be a linear function of distance along the channel. The expressions relating to the velocity distribution are obtained and effects of different values of various physical parameters are calculated numerically and shown graphically.

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