scholarly journals Free convection between vertical concentric annuli with induced magnetic field when inner cylinder is electrically conducting

2014 ◽  
Vol 13 (10) ◽  
pp. 5063-5074 ◽  
Author(s):  
SARVESHA NAND ◽  
Ashok Kumar Singh
Keyword(s):  
Magnetic Field ◽  
Radiation Heat Transfer ◽  
Outer Cylinder ◽  
Boussinesq Approximation ◽  
Constant Heat Flux ◽  
Physical Parameters ◽  
Induced Current ◽  
Induced Magnetic Field ◽  
Radial Magnetic Field ◽  
Electrically Conducting

An analysis is made for the fully developed laminar free convective flow in an open ended vertical concentric annuli with constant heat flux and constant temperature on the inner and outer walls, in the presence of a radial magnetic field. The length of the cylinder is assumed to be infinite and radiation heat transfer from the hot surface is assumed to be negligible. The inner cylinder is taken to be magnetic conducting while the outer cylinder is non-conducting. Buoyancy effect is also considered along with Boussinesq approximation. The induced magnetic field is taken into account arising due to the motion of an electrically conducting fluid. The governing linear simultaneous ordinary differential equations are first obtained in the non dimensional form and solved analytically for the velocity, induced magnetic field, temperature field and  then skin-friction and induced current density are obtained. The expressions for the fluid flux and induced current flux in non-dimensional form have been also obtained. The effects of governing physical parameters occurring in the model are shown on the graphs and tables.

Article

1998 ◽  
Vol 76 (5) ◽  
pp. 391-401
Author(s):  
MES Ahmed ◽  
H A Attia
Keyword(s):  
Magnetic Field ◽  
Outer Cylinder ◽  
Constant Heat Flux ◽  
Constant Heat ◽  
Eccentric Annulus ◽  
Electrically Conducting ◽  
Flow And Heat Transfer ◽  
The Magnetic Field ◽  
External Uniform Magnetic Field ◽  
Steady Laminar

The steady laminar flow and heat transfer of an incompressible, electrically conducting, non-Newtonian fluid in an eccentric annulus are studied in the presence of an external uniform magnetic field. The inner cylinder is subject to a constant heat flux while the outer cylinder is adiabatic and the viscous and Joule dissipations are taken into consideration. A numerical solution for the governing partial differential equations is developed and the influence of the magnetic field on both the velocity and temperature distributions are discussed.PACS Nos.: 47.65, 47.50, 47.15C

Stability of Taylor–Couette Magnetoconvection With Radial Temperature Gradient and Constant Heat Flux at the Outer Cylinder

2006 ◽  
Vol 129 (3) ◽  
pp. 302-310 ◽  
Author(s):  
R. K. Deka ◽  
A. S. Gupta
Keyword(s):  
Magnetic Field ◽  
Heat Flux ◽  
Outer Cylinder ◽  
Constant Heat Flux ◽  
Taylor Number ◽  
Wave Number ◽  
Constant Heat ◽  
Radial Temperature ◽  
Electrically Conducting ◽  
Wide Gap

An analysis is made of the linear stability of wide-gap hydromagnetic (MHD) dissipative Couette flow of an incompressible electrically conducting fluid between two rotating concentric circular cylinders in the presence of a uniform axial magnetic field. A constant heat flux is applied at the outer cylinder and the inner cylinder is kept at a constant temperature. Both types of boundary conditions viz; perfectly electrically conducting and electrically nonconducting walls are examined. The three cases of μ<0 (counter-rotating), μ>0 (co-rotating), and μ=0 (stationary outer cylinder) are considered. Assuming very small magnetic Prandtl number Pm, the wide-gap perturbation equations are derived and solved by a direct numerical procedure. It is found that for given values of the radius ratio η and the heat flux parameter N, the critical Taylor number Tc at the onset of instability increases with increase in Hartmann number Q for both conducting and nonconducting walls thus establishing the stabilizing influence of the magnetic field. Further it is found that insulating walls are more destabilizing than the conducting walls. It is observed that for given values of η and Q, the critical Taylor number Tc decreases with increase in N. The analysis further reveals that for μ=0 and perfectly conducting walls, the critical wave number ac is not a monotonic function of Q but first increases, reaches a maximum and then decreases with further increase in Q. It is also observed that while ac is a monotonic decreasing function of μ for N=0, in the presence of heat flux (N=1), ac has a maximum at a negative value of μ (counter-rotating cylinders).

scholarly journals Crossbreed impact of double-diffusivity convection on peristaltic pumping of magneto Sisko nanofluids in non-uniform inclined channel: A bio-nanoengineering model

2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110336
Author(s):  
Safia Akram ◽  
Maria Athar ◽  
Khalid Saeed ◽  
Alia Razia
Keyword(s):  
Mathematical Modeling ◽  
Magnetic Field ◽  
Physical Parameters ◽  
Induced Magnetic Field ◽  
Long Wavelength ◽  
Inclined Channel ◽  
Graphical Data ◽  
Peristaltic Pumping ◽  
Highly Nonlinear ◽  
Linear Pdes

The consequences of double-diffusivity convection on the peristaltic transport of Sisko nanofluids in the non-uniform inclined channel and induced magnetic field are discussed in this article. The mathematical modeling of Sisko nanofluids with induced magnetic field and double-diffusivity convection is given. To simplify PDEs that are highly nonlinear in nature, the low but finite Reynolds number, and long wavelength estimation are used. The Numerical solution is calculated for the non-linear PDEs. The exact solution of concentration, temperature and nanoparticle are obtained. The effect of various physical parameters of flow quantities is shown in numerical and graphical data. The outcomes show that as the thermophoresis and Dufour parameters are raised, the profiles of temperature, concentration, and nanoparticle fraction all significantly increase.

Magnetohydrodynamic lubrication flow between parallel rotating disks

1962 ◽  
Vol 13 (1) ◽  
pp. 21-32 ◽  
Author(s):  
W. F. Hughes ◽  
R. A. Elco
Keyword(s):  
Magnetic Field ◽  
Axial Magnetic Field ◽  
Load Capacity ◽  
Electrical Energy ◽  
Axial Current ◽  
Frictional Torque ◽  
Rotating Disks ◽  
Radial Magnetic Field ◽  
Electrically Conducting ◽  
Parallel Disks

The motion of an electrically conducting, incompressible, viscous fluid in the presence of a magnetic field is analyzed for flow between two parallel disks, one of which rotates at a constant angular velocity. The specific application to liquid metal lubrication in thrust bearings is considered. The two field configurations discussed are: an axial magnetic field with a radial current and a radial magnetic field with an axial current. It is shown that the load capacity of the bearing is dependent on the MHD interactions in the fluid and that the frictional torque on the rotor can be made zero for both field configurations by supplying electrical energy through the electrodes to the fluid.

Fluid flow analysis of cilia beating in a curved channel in the presence of magnetic field and heat transfer

2020 ◽  
Vol 98 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Hina Sadaf ◽  
S. Nadeem
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Velocity Profile ◽  
Flow Analysis ◽  
Fluid Motion ◽  
Flow Characteristics ◽  
Physical Parameters ◽  
Curved Channel ◽  
Radial Magnetic Field ◽  
Fluid Flow Analysis

This paper investigates fluid motion generated by cilia and a pressure gradient in a curved channel. The flow analysis is carried out in the presence of heat transfer and radial magnetic field. The leading equations are simplified under the familiar suppositions of large wavelength and small Reynolds number approximations. An exact solution has been developed for the velocity profile. The flow characteristics of the viscous fluid are computed in the presence of cilia and metachronal wave velocity. The effects of several stimulating parameters on the flow and heat transfer are studied in detail through graphs. It is found that symmetry of the velocity profile is broken owing to bending of the channel. The radially varying magnetic field decreases the velocity field, but near the left ciliated wall it induces the opposite behavior. It is also found that velocity profile increases due to increase in buoyancy forces throughout the domain. Numerical consequences for velocity profile are also accessible in the table for diverse values of the physical parameters.

scholarly journals Effects of Thermal Radiation, Heat Generation, and Induced Magnetic Field on Hydromagnetic Free Convection Flow of Couple Stress Fluid in an Isoflux-Isothermal Vertical Channel

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Hasan Nihal Zaidi ◽  
Mohammed Yousif ◽  
S. Nazia Nasreen
Keyword(s):  
Magnetic Field ◽  
Couple Stress ◽  
Channel Wall ◽  
Vertical Channel ◽  
Convection Flow ◽  
Induced Current ◽  
Induced Magnetic Field ◽  
Radiation Heat ◽  
Free Convection Flow ◽  
Radiation Heat Generation

The study scrutinizes the effects of thermal radiation, heat generation, and induced magnetic field on steady, fully developed hydromagnetic free convection flow of an incompressible viscous and electrically conducting couple stress fluid in a vertical channel. The channel walls are maintained at an isoflux-isothermal condition, such that the left channel wall is maintained at a constant heat flux. In contrast, the right channel wall is maintained at a constant temperature. The governing simultaneous equations are solved analytically utilizing the method of undetermined coefficient, and closed form solutions in dimensionless form have been acquired for the velocity field, the induced magnetic field, and the temperature field. The expression for the induced current density has been also obtained. A parametric study for the velocity, temperature, and induced magnetic field profiles, as well as for the skin-friction coefficient, Nusselt number, and induced current density, is conducted and discussed graphically.

The effect of a radial magnetic field on the stability of Couette flow

1994 ◽  
Vol 72 (5-6) ◽  
pp. 258-265 ◽  
Author(s):  
M. A. Ali
Keyword(s):  
Magnetic Field ◽  
Eigenvalue Problem ◽  
Incompressible Fluid ◽  
Couette Flow ◽  
Wave Number ◽  
Rotating Cylinders ◽  
Radial Magnetic Field ◽  
Electrically Conducting ◽  
Angular Velocities ◽  
The Stability

The effect of a radial magnetic field on the stability of an electrically conducting incompressible fluid between two concentric rotating cylinders is considered. The eigenvalue problem for determining the critical Taylor number TC and the corresponding wave number aC is solved numerically for different values of ±μ(= Ω2/Ω1), (where Ω1, and Ω2 are me angular velocities of the inner and outer cylinders, respectively) and for different gap sizes. It is observed that the radial magnetic field stabilizes the flow. This effect is more pronounced for cylinders that are corotating as compared with counter-rotating cylinders or the situation where only the inner one is rotating.

Induced magnetic field influences on blood flow through an anisotropically tapered elastic artery with overlapping stenosis in an annulus

2011 ◽  
Vol 89 (2) ◽  
pp. 201-212 ◽  
Author(s):  
Kh. S. Mekheimer ◽  
Mohammed H. Haroun ◽  
M. A. El Kot
Keyword(s):  
Magnetic Field ◽  
Blood Flow ◽  
Current Density ◽  
Axial Velocity ◽  
Mathematical Representation ◽  
Physical Parameters ◽  
Maximum Height ◽  
Induced Magnetic Field ◽  
Flow Through ◽  
Elastic Artery

A mathematical model for blood flow through an elastic artery with overlapping stenosis under the effect of induced magnetic field is presented. The present theoretical model may be considered as a mathematical representation to the movement of conductive physiological fluid through coaxial tubes such that the inner tube is uniform and rigid, representing a catheter tube, while the outer tube is an anisotropically tapered elastic cylindrical tube filled with a viscous incompressible electrically conducting fluid, representing blood. The analysis is carried out for an artery with mild local narrowing in its lumen, forming a stenosis. Analytical expressions for the stream function, the magnetic force function, the axial velocity, the axial induced magnetic field, and the distribution of the current density are obtained. The results for the resistance impedance, the wall shear stress distribution, the axial velocity, the axial induced magnetic field, and distribution of the current density have been computed numerically, and the results were studied for various values of the physical parameters, such as the the Hartmann number Ha, the magnetic Reynolds number Rm, the taper angle ϕ, the maximum height of stenosis δ, the degree of anisotropy of the vessel wall n, and the contributions of the elastic constraints to the total tethering K.

Sign in / Sign up

Export Citation Format

Share Document