Flow of an electrically conducting non-newtonian fluid between two rotating coaxial cones in the presence of external magnetic field due to an axial current

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.

Download Full-text

Numerical analysis of the onset of longitudinal convective rolls in a porous medium saturated by an electrically conducting nanofluid in the presence of an external magnetic field

Results in Physics ◽

10.1016/j.rinp.2017.06.003 ◽

2017 ◽

Vol 7 ◽

pp. 2134-2152 ◽

Cited By ~ 47

Author(s):

Abderrahim Wakif ◽

Zoubair Boulahia ◽

Rachid Sehaqui

Keyword(s):

Magnetic Field ◽

Porous Medium ◽

Numerical Analysis ◽

External Magnetic Field ◽

Electrically Conducting ◽

Convective Rolls

Download Full-text

Soret effects due to natural convection in a non-Newtonian fluid flow in porous medium with heat and mass transfer

Journal of Naval Architecture and Marine Engineering ◽

10.3329/jname.v11i2.17563 ◽

2014 ◽

Vol 11 (2) ◽

pp. 147-156 ◽

Cited By ~ 4

Author(s):

M.C Raju ◽

S.V.K Varma

Keyword(s):

Magnetic Field ◽

Porous Medium ◽

Fluid Flow ◽

Newtonian Fluid ◽

Porous Plate ◽

Sink Strength ◽

Suction Parameter ◽

Electrically Conducting ◽

Highly Nonlinear ◽

Constant Suction

The problem of unsteady MHD free convective, incompressible electrically conducting, non-Newtonian fluid through porous medium bounded by an infinite porous plate in the presence of constant suction has been studied. A magnetic field of uniform strength is assumed to be applied normal to the plate. The equations governing the fluid flow which are highly nonlinear are reduced to linear by using perturbation method and have been solved subject to the relevant boundary conditions. It is noted that the velocity of the fluid is increased as Soret number and suction parameter increase, whereas reverse phenomenon is observed in case of magnetic field strength and sink strength. DOI: http://dx.doi.org/10.3329/jname.v11i2.17563

Download Full-text

Hiemenz magnetic flow of a non-Newtonian fluid of second grade with heat transfer

Canadian Journal of Physics ◽

10.1139/p00-047 ◽

2000 ◽

Vol 78 (9) ◽

pp. 875-882 ◽

Cited By ~ 4

Author(s):

H A Attia

Keyword(s):

Magnetic Field ◽

Heat Transfer ◽

Newtonian Fluid ◽

Second Grade ◽

Magnetic Flow ◽

Electrically Conducting ◽

Flow And Heat Transfer ◽

Energy Equations ◽

The Magnetic Field ◽

Steady Laminar

The steady laminar flow of an incompressible viscous electrically conducting non-Newtonian fluid of second grade impinging normal to a plane wall with heat transfer is investigated. An externally applied uniform magnetic field is applied normal to the wall, which is maintained at a constant temperature. A numerical solution for the governing momentum and energy equations is obtained. The effect of the characteristics of the non-Newtonian fluid and the magnetic field on both the flow and heat transfer is outlined. PACS Nos.: 47.50 and 47.15

Download Full-text

The Thermoelectric-Hydromagnetic Pump

Journal of Heat Transfer ◽

10.1115/1.3687089 ◽

1964 ◽

Vol 86 (2) ◽

pp. 166-168 ◽

Cited By ~ 3

Author(s):

J. F. Osterle ◽

S. W. Angrist

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Magnetic Flux ◽

Flux Density ◽

Pressure Rise ◽

Maximum Efficiency ◽

Magnetic Flux Density ◽

Optimum Thickness ◽

Pumping Power ◽

Electrically Conducting

A thermally powered pump for fluids which are electrically conducting, which utilizes the Lorentz force between an electric current induced by the Seebeck effect, and an external magnetic field is examined. The pressure rise in the pump is found to be proportional to the magnetic flux density while the flow rate is found to be inversely proportional to the magnetic flux density. Thus the pumping power and efficiency (both being proportional to the product of pressure rise and flow) are independent of the applied magnetic field. Calculations for a pump with constantan walls handling sodium and utilizing a temperature difference of 300 deg C show that a maximum efficiency of close to seven-tenths of a percent is possible. If the same pump is constructed with optimum thickness walls made of the semiconductor AgSbTe2, it would have an efficiency of nearly six percent.

Download Full-text

Reverse Flow in Magnetoconvection of Two Immiscible Fluids in a Vertical Channel

Journal of Fluids Engineering ◽

10.1115/1.4036670 ◽

2017 ◽

Vol 139 (10) ◽

Cited By ~ 5

Author(s):

Alessandra Borrelli ◽

Giulia Giantesio ◽

Maria Cristina Patria

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Mixed Convection ◽

Newtonian Fluid ◽

Hartmann Number ◽

Reverse Flow ◽

Vertical Channel ◽

Boussinesq Approximation ◽

Immiscible Fluids ◽

Induced Magnetic Field

This paper concerns the study of the influence of an external magnetic field on the reverse flow occurring in the steady mixed convection of two Newtonian immiscible fluids filling a vertical channel under the Oberbeck–Boussinesq approximation. The two isothermal boundaries are kept either at different or at equal temperatures. The velocity, the temperature, and the induced magnetic field are obtained analytically. The results are presented graphically and discussed for various values of the parameters involved in the problem (in particular, the Hartmann number and the buoyancy coefficient) and are compared with those for a single Newtonian fluid. The occurrence of the reverse flow is explained and carefully studied.

Download Full-text

Three-Dimensional Flow in a Driven Cavity Subjected to an External Magnetic Field

Journal of Fluids Engineering ◽

10.1115/1.4029731 ◽

2015 ◽

Vol 137 (7) ◽

Cited By ~ 9

Author(s):

K. Jin ◽

S. P. Vanka ◽

B. G. Thomas

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Graphics Processing Unit ◽

Three Dimensional ◽

Magnetic Interaction ◽

Processing Unit ◽

Field Equations ◽

Driven Cavity ◽

Electrically Conducting ◽

The Magnetic Field

In this paper, we study the three-dimensional (3D) flow of an electrically conducting fluid in a cubic cavity with the top wall moving and subjected to an external magnetic field. The governing flow and electromagnetic field equations are integrated by a second-order space and time accurate numerical scheme, implemented on a graphics processing unit (GPU) with high parallel efficiency. Solutions for several Reynolds and Stuart numbers have been obtained on sufficiently fine grids to achieve grid independent solutions. As expected, the magnetic field significantly influences the circulation in the cavity and modifies the shape and locations of the primary and secondary eddies. The observed flow patterns are illustrated graphically as well as through selected line plots and tabulated data. With increasing magnetic field strength, the center of the primary eddy is seen to shift to the top right corner. Further, situations where the flow is unsteady in the absence of the magnetic field have become steady after a certain value of the magnetic interaction parameter.

Download Full-text

An instability of laminar flow of mercury caused by an external magnetic field

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1955.0265 ◽

1955 ◽

Vol 233 (1194) ◽

pp. 299-302 ◽

Cited By ~ 38

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Laminar Flow ◽

Viscous Flow ◽

Fluid Layer ◽

The State ◽

Conducting Liquid ◽

Rotating Cylinders ◽

Electrically Conducting ◽

Gravitational Stability

Recent research on magneto-hydrodynamics has indicated the existence of a great number of situations where a magnetic field stabilizes the state of motion of an electrically conducting liquid. Examples have been given by Hartmann & Lazarus (1937), Murgatroyd (1953 a,b ), Shercliff (1953), and Stuart (1954) for viscous flow between parallel planes and in pipes, by Chandrasekhar (1953) and Lehnert (1952 a ) for viscous flow between rotating cylinders, by Chandrasekhar & Fermi (1953) for problems of gravitational stability and by Chandrasekhar (1952) and Nakagawa (1955) for the inhibition of convection in a fluid layer.

Download Full-text

WKB thresholds of standard, helical, and azimuthal magnetorotational instability

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312019771 ◽

2012 ◽

Vol 8 (S290) ◽

pp. 233-234 ◽

Cited By ~ 2

Author(s):

Oleg Kirillov ◽

Frank Stefani

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Prandtl Number ◽

Local Stability ◽

Rotating Flows ◽

Rossby Number ◽

Magnetorotational Instability ◽

Electrically Conducting ◽

Magnetic Prandtl Number ◽

Wavelength Approximation

AbstractWe consider rotating flows of an electrically conducting, viscous and resistive fluid in an external magnetic field with arbitrary combinations of axial and azimuthal components. Within the short-wavelength approximation, the local stability of the flow is studied with respect to perturbations of arbitrary azimuthal wavenumbers. In the limit of vanishing magnetic Prandtl number (Pm) we find that the maximum critical Rossby number (Ro) for the occurrence of the magnetorotational instability (MRI) is universally governed by the Liu limit ${\rm Ro}_{Liu}=2-2\sqrt{2}\approx -0.828$ which is below the value for Keplerian rotation RoKepler = −0.75.

Download Full-text

Effects of variable viscosity and thermal conductivity on unsteady MHD flow of non-Newtonian fluid over a stretching porous sheet

Thermal Science ◽

10.2298/tsci110529025r ◽

2013 ◽

Vol 17 (4) ◽

pp. 1035-1047 ◽

Cited By ~ 2

Author(s):

Abdel-Gamal Rahman

Keyword(s):

Magnetic Field ◽

Heat Transfer ◽

Thermal Conductivity ◽

Porous Medium ◽

Differential Equations ◽

Newtonian Fluid ◽

Variable Viscosity ◽

Mhd Flow ◽

Transverse Magnetic ◽

Electrically Conducting

The unsteady flow and heat transfer in an incompressible laminar, electrically conducting and non-Newtonian fluid over a non-isothermal stretching sheet with the variation in the viscosity and thermal conductivity in a porous medium by the influence of an external transverse magnetic field have been obtained and studied numerically. By using similarity analysis the governing differential equations are transformed into a set of non-linear coupled ordinary differential equations which are solved numerically. Numerical results were presented for velocity and temperature profiles for different parameters of the problem as power law parameter, unsteadiness parameter, radiation parameter, magnetic field parameter, porous medium parameter, temperature buoyancy parameter, Prandtl parameter, modified Eckert parameter, Joule heating parameter , heat source/sink parameter and others. A comparison with previously published work has been carried out and the results are found to be in good agreement. Also the effects of the pertinent parameters on the skin friction and the rate of heat transfer are obtained and discussed numerically and illustrated graphically.

Download Full-text