Electromagnetic Pump With Thin Metal Walls

1994 ◽  
Vol 116 (2) ◽  
pp. 298-302
Author(s):  
N. Ma ◽  
T. J. Moon ◽  
J. S. Walker
Keyword(s):  
Magnetic Field ◽  
Boundary Layers ◽  
Metal Flow ◽  
Side Wall ◽  
Transverse Magnetic ◽  
Thin Metal ◽  
Total Flow ◽  
Electromagnetic Pump ◽  
Liquid Metal Flow ◽  
Side Walls

This paper treats a liquid-metal flow in a rectangular duct with a strong, uniform, transverse magnetic field and with thin metal walls, except for two finite-length, perfectly conducting electrodes in the side walls, which are parallel to the magnetic field. There are large velocities inside the boundary layers adjacent to the thin metal side walls, but not inside the layers adjacent to the electrodes. Upstream and downstream of the electrodes, a significant fraction of the total flow leaves and enters the side-wall boundary layers, respectively. For the particular duct treated here, the fully developed side layers, which carry 38.8 percent of the total flow, are realized at a distance of three characteristic lengths from the ends of the electrodes.

Three-dimensional MHD duct flows with strong transverse magnetic fields. Part 2. Variable-area rectangular ducts with conducting sides

1971 ◽  
Vol 46 (4) ◽  
pp. 657-684 ◽  
Author(s):  
J. S. Walker ◽  
G. S. S. Ludford ◽  
J. C. R. Hunt
Keyword(s):  
Magnetic Field ◽  
Boundary Layers ◽  
Three Dimensional ◽  
Side Wall ◽  
Transverse Magnetic ◽  
Reverse Direction ◽  
Wall Boundary ◽  
Strong Transverse ◽  
Side Walls ◽  
The Magnetic Field

In this paper the general analysis, developed in part 1, of three-dimensional duct flows subject to a strong transverse magnetic field is used to examine the flow in diverging ducts of rectangular cross-section. It is found that, with the magnetic field parallel to one pair of the sides, the essential problem is the analysis of the boundary layers on these (side) walls. Assuming that they are highly conducting and that those perpendicular to the magnetic field are non-conducting, the flow is found to have some interesting properties: if the top and bottom walls diverge, the side walls remaining parallel, then an O(1) velocity overshoot occurs in the side-wall boundary layers; but if the top and bottom walls remain parallel, the side walls diverging, these boundary layers have conventional velocity profiles. The most interesting flows occur when both pairs of walls diverge, when it is found that large, 0(M½), velocities occur in the side-wall boundary layers, either in the direction of the mean flow or in the reverse direction, depending on the geometry of the duct and the external electric circuit!The mathematical analysis involves the solution of a formidable integral equation which, however, does have analytic solutions for some special types of duct.

Liquid-metal flow in a rectangular duct with a strong non-uniform magnetic field

1984 ◽  
Vol 139 ◽  
pp. 309-324 ◽  
Author(s):  
John C. Petrykowski ◽  
John S. Walker
Keyword(s):  
Magnetic Field ◽  
Liquid Metal ◽  
Metal Flow ◽  
Velocity Profiles ◽  
Transverse Magnetic ◽  
Secondary Flows ◽  
Rectangular Duct ◽  
Liquid Metal Flow ◽  
Displacement Thickness ◽  
The Magnetic Field

Liquid-metal flows in rectangular ducts having electrically insulating tops and bottoms and perfectly conducting sides and in the presence of strong, polar, transverse magnetic fields are examined. Solutions are presented for the boundary layers adjacent to the sides that are parallel to the magnetic field. Overshoots in the radial velocity profiles show that the side layers have zero displacement thickness and do not perturb the inviscid core. Very weak secondary flows involve four significant vortices, as reflected in the polar velocity profiles.

Thermal convection studies in liquid metal flow inside a horizontal duct under the influence of transverse magnetic field

2020 ◽  
Vol 32 (6) ◽  
pp. 067107 ◽  
Author(s):  
S. Sahu ◽  
C. Courtessole ◽  
A. Ranjan ◽  
R. Bhattacharyay ◽  
T. Sketchley ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Liquid Metal ◽  
Transverse Magnetic Field ◽  
Thermal Convection ◽  
Metal Flow ◽  
Transverse Magnetic ◽  
Liquid Metal Flow

Three-dimensional MHD duct flows with strong transverse magnetic fields. Part 3. Variable-area rectangular ducts with insulating walls

1972 ◽  
Vol 56 (1) ◽  
pp. 121-141 ◽  
Author(s):  
J. S. Walker ◽  
G. S. S. Ludford ◽  
J. C. R. Hunt
Keyword(s):  
Magnetic Field ◽  
Boundary Layers ◽  
Numerical Solutions ◽  
Rectangular Cross Section ◽  
Flow Direction ◽  
Three Dimensional ◽  
Side Wall ◽  
Transverse Magnetic ◽  
Wall Boundary ◽  
Strong Transverse

The general analysis developed in Parts 1 and 2 of three-dimensional duct flows subject to a strong transverse magnetic field is used to examine the flow in diverging ducts of rectangular cross-section, the walls of which are electrically non-conducting. A dramatically different flow is found in this case from that studied in Part 2, where the side walls parallel to the magnetic field were highly conducting. Now it is found that the core velocity normalized with respect to the mean velocity is of O(M−½) while the velocity in the side-wall boundary layers is of O(M½), so that these boundary layers carry most of the flow. The problem of entry is solved by analysing the change from fully developed Hartmann flow in a rectangular duct to the flow in the diverging duct. It is found that the disturbance in the upstream duct decays exponentially. The analysis of the side-wall boundary layers is more difficult than that in Part 1 on account of the different boundary conditions and requires the solution of two coupled integro-differential equations. Numerical solutions are obtained for a duct whose width increases linearly in the flow direction.

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