Effect of Axial Magnetic Field Strengths on Radial Velocity Field in Liquid Bridge under Microgravity

2012 ◽  
Vol 256-259 ◽  
pp. 1670-1673
Author(s):  
Ru Quan Liang ◽  
Shuo Yang ◽  
Jun Hong Ji ◽  
Ji Cheng He
Keyword(s):  
Magnetic Field ◽  
Liquid Bridge ◽  
Axial Magnetic Field ◽  
Phase Interface ◽  
Mass Conservation ◽  
Inhibitory Effect ◽  
Two Phase ◽  
Conservation Level ◽  
The Magnetic Field ◽  
Field Strengths

This article studies on the effect of magnetic field strengths on the flow field in a liquid bridge under zero gravity. The mass conservation level set method is used to track the two-phase interface. The results show that inhibitory effect of additional axial magnetic field on thermocapillary convection within liquid bridge is obvious, and this kind of inhibitory effect increasing as the magnetic field strength is strengthened.

Nonlinear evolution of a wave packet propagating along a hot magnetoplasma column

1987 ◽  
Vol 37 (1) ◽  
pp. 107-115
Author(s):  
B. Ghosh ◽  
K. P. Das
Keyword(s):  
Magnetic Field ◽  
Multiple Scales ◽  
Nonlinear Evolution ◽  
Axial Magnetic Field ◽  
Modulational Instability ◽  
Wave Train ◽  
Dielectric Medium ◽  
Ion Effects ◽  
The Magnetic Field ◽  
Uniform Plasma

The method of multiple scales is used to derive a nonlinear Schrödinger equation, which describes the nonlinear evolution of electron plasma ‘slow waves’ propagating along a hot cylindrical plasma column, surrounded by a dielectric medium and immersed in an essentially infinite axial magnetic field. The temperature is included as well as mobile ion effects for ail possible modes of propagation along the magnetic field. From this equation the condition for modulational instability for a uniform plasma wave train is determined.

scholarly journals DC Glow Discharge in Axial Magnetic Field at Low Pressures

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Shen Gao ◽  
Shixiu Chen ◽  
Zengchao Ji ◽  
Wei Tian ◽  
Jun Chen
Keyword(s):  
Magnetic Field ◽  
Glow Discharge ◽  
Differential Equations ◽  
Axial Magnetic Field ◽  
Glow Discharge Plasma ◽  
Dc Glow Discharge ◽  
Fluid Approximation ◽  
Low Pressures ◽  
Physical Quantities ◽  
The Magnetic Field

On the basis of fluid approximation, an improved version of the model for the description of dc glow discharge plasma in the axial magnetic field was successfully developed. The model has yielded a set of analytic formulas for the physical quantities concerned from the electron and ion fluids equations and Poisson equation. The calculated results satisfy the practical boundary conditions. Results obtained from the model reveal that although the differential equations under the condition of axial magnetic field are consistent with the differential equations without considering the magnetic field, the solution of the equations is not completely consistent. The results show that the stronger the magnetic field, the greater the plasma density.

scholarly journals The effect of uniform magnetic field on spatial-temporal evolution of thermocapillary convection with the silicon oil based ferrofluid

2020 ◽  
Vol 24 (6 Part B) ◽  
pp. 4159-4171
Author(s):  
Shuo Yang ◽  
Rui Ma ◽  
Qiaosheng Deng ◽  
Guofeng Wang ◽  
Yu Gao ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Free Surface ◽  
Transverse Magnetic Field ◽  
Liquid Bridge ◽  
Thermocapillary Convection ◽  
Surface Deformation ◽  
Axial Magnetic Field ◽  
Transverse Magnetic ◽  
Surface Flow ◽  
Silicon Oil

A uniform axial or transverse magnetic field is applied on the silicon oil based ferrofluid of high Prandtl number fluid (Pr ? 111.67), and the effect of magnetic field on the thermocapillary convection is investigated. It is shown that the location of vortex core of thermocapillary convection is mainly near the free surface of liquid bridge due to the inhibition of the axial magnetic field. A velocity stagnation region is formed inside the liquid bridge under the axial magnetic field (B = 0.3-0.5 T). The disturbance of bulk reflux and surface flow is suppressed by the increasing axial magnetic field. There is a dynamic response of free surface deformation to the axial magnetic field, and then the contact angle variation of the free surface at the hot corner is as following, ?hot, B = 0.5 T = 83.34? > ?hot, B = 0.3 T = 72.16? > > ?hot,B = 0.1 T = 54.21? > ?hot, B = 0 T = 43.33?. The results show that temperature distribution near the free surface is less and less affected by thermocapillary convection with the increasing magnetic field, and it presents a characteristic of heat-conduction. In addition, the transverse magnetic field does not realize the fundamental inhibition for thermocapillary convection, but it transfers the influence of thermocapillary convection to the free surface.

scholarly journals Magnetic Field Strengths of Spiral Galaxies and the Far-Infrared/Radio Correlation

1990 ◽  
Vol 140 ◽  
pp. 241-241
Author(s):  
A. J. Fitt ◽  
P. Alexander
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Distribution ◽  
Detection Rate ◽  
Spiral Galaxies ◽  
Far Infrared ◽  
Magnetic Field Distribution ◽  
Selection Effects ◽  
The Magnetic Field ◽  
Field Strengths

We have calculated equipartition magnetic fields for a complete, optically-selected sample of 165 spiral galaxies. The magnetic field distribution (fig. 1) is type independent, and shows remarkably little spread in values, around 1 decade in B. This is not due to selection effects because of the nature of the sample and the 95 percent detection rate.

scholarly journals Programmable shunt valve interactions with osseointegrated hearing devices

2017 ◽  
Vol 19 (4) ◽  
pp. 384-390
Author(s):  
Matthew J. Pierson ◽  
Daniel Wehrmann ◽  
J. Andrew Albers ◽  
Najib E. El Tecle ◽  
Dary Costa ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Shunt Valve ◽  
Vp Shunt ◽  
Magnetic Attachment ◽  
Hearing Devices ◽  
Programmable Valves ◽  
The Magnetic Field ◽  
Field Strengths

OBJECTIVE Patients with ventriculoperitoneal (VP) shunts with programmable valves who would benefit from osseointegrated hearing devices (OIHDs) represent a unique population. The aim of this study was to evaluate the magnetic field strengths of 4 OIHDs and their interactions with 5 programmable VP shunt valves. METHODS Magnetic field strength was measured as a function of distance for each hearing device (Cochlear Baha 5, Cochlear Baha BP110, Oticon Ponto Plus Power, and Medtronic Sophono) in the following modes: inactive, active in quiet, and active in 60 decibels of background noise in the sound booth. The hearing devices were introduced to each shunt valve (Aesculap proGAV, Aesculap proGAV 2.0, Codman Hakim, Codman Certas, and Medtronic Strata II) also as a function of distance in these identical 3 settings. Each trial was repeated 5 times. Between each trial, the valves were assessed for a change in setting. Finally, using a skull model, the devices were introduced to each other in standard anatomical locations and the valves were assessed for a change in settings. RESULTS The maximum magnetic field strengths generated by the Cochlear Baha 5, BP110, and Oticon OIHDs were 1.1, 36.2, and 48.7 gauss (G), respectively. The maximum strength generated by the Sophono device was > 800 G. The magnetic field strength of the hearing devices decreased markedly with increasing distance from the device. The strength of the Sophono's magnetic attachment decreased to 34.8 G at 5 mm. The Codman Hakim, Codman Certas, and Medtronic Strata II valve settings changed when rotating the valves next to the Sophono abutment. No other changes in valve settings occurred in the distance or anatomical models for any other trials. CONCLUSIONS This is the first study evaluating the interaction between OIHDs and programmable VP shunt valves. The findings suggest that it is safe to use these devices together without having to switch to a nonprogrammable valve or move the shunt valve to a more distant location. Still, care should be taken if the Sophono device is used to ensure that the valve is ≥ 5 mm away from the magnetic attachment.

Schwingung eines Plasmazylinders in einem axialen Magnetfeld II

1960 ◽  
Vol 15 (3) ◽  
pp. 220-226 ◽  
Author(s):  
Klaus Körper
Keyword(s):  
Magnetic Field ◽  
Refractive Index ◽  
External Magnetic Field ◽  
Field Strength ◽  
Axial Magnetic Field ◽  
Surface Current ◽  
The Other ◽  
Plasma Cylinder ◽  
Resonance Frequencies ◽  
The Magnetic Field

Radial oscillations are excited in a homogeneous infinite plasma cylinder in a homogeneous axial magnetic field by a surface current which is homogeneous in the axial and azimuthal directions. The modes of oscillations corresponding to the axial and azimuthal components of current are not coupled, and so they may be analysed separately. The magnetic field in the plasma and vacuum is obtained, and the indices of refraction for both types of oscillations are discussed thoroughly. When the currents are parallel to the external magnetic field, the oscillations are characterized by the refractive index of Eccles. On the other hand, when the current is perpendicular to the magnetic field two resonance frequencies exist, which depend on the density of the plasma and the magnetic field strength. — In the latter case the radial characteristic oscillations of the plasma cylinder in an external magnetic field are considered.

Buoyant Convection During the Growth of Compound Semiconductors by the Liquid-Encapsulated Czochralski Process With an Axial Magnetic Field and With a Non-Axisymmetric Temperature

1996 ◽  
Vol 118 (1) ◽  
pp. 155-159 ◽  
Author(s):  
Nancy Ma ◽  
J. S. Walker
Keyword(s):  
Magnetic Field ◽  
Axial Magnetic Field ◽  
Compound Semiconductors ◽  
Vertical Axis ◽  
Crucible Wall ◽  
Buoyant Convection ◽  
Axisymmetric Part ◽  
Czochralski Process ◽  
Axisymmetric Temperature ◽  
The Magnetic Field

This paper treats the buoyant convection of a molten semiconductor in a cylindrical crucible with a vertical axis, with a uniform vertical magnetic field, and with a non-axisymmetric temperature. Most previous treatments of melt motions with vertical magnetic fields have assumed that the temperature and buoyant convection were axisymmetric. In reality, the temperature and resultant buoyant convection often deviate significantly from axisymmetry. For a given non-axisymmetric temperature, the electromagnetic suppression of the axisymmetric part of the buoyant convection is stronger than that of the non-axisymmetric part, so that the deviation from an axisymmetric melt motion increases as the magnetic field strength is increased. The non-axisymmetric part of the buoyant convection includes relatively strong azimuthal velocities adjacent to the electrically insulating vertical crucible wall, because this wall blocks the radial electric currents needed to suppress azimuthal velocities.

scholarly journals Ion energy increase in laser-generated plasma expanding through axial magnetic field trap

2007 ◽  
Vol 25 (3) ◽  
pp. 453-464 ◽  
Author(s):  
L. Torrisi ◽  
D. Margarone ◽  
S. Gammino ◽  
L. Andò
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Electric Fields ◽  
Axial Magnetic Field ◽  
Ion Beam ◽  
High Vacuum ◽  
Target Surface ◽  
Axial Direction ◽  
Ion Interactions ◽  
The Magnetic Field

Laser-generated plasma is obtained in high vacuum (10−7 mbar) by irradiation of metallic targets (Al, Cu, Ta) with laser beam with intensities of the order of 1010 W/cm2. An Nd:Yag laser operating at 1064 nm wavelength, 9 ns pulse width, and 500 mJ maximum pulse energy is used. Time of flight measurements of ion emission along the direction normal to the target surface were performed with an ion collector. Measurements with and without a 0.1 Tesla magnetic field, directed along the normal to the target surface, have been taken for different target-detector distances and for increasing laser pulse intensity. Results have demonstrated that the magnetic field configuration creates an electron trap in front of the target surface along the axial direction. Electric fields inside the trap induce ion acceleration; the presence of electron bundles not only focuses the ion beam but also increases its energy, mean charge state and current. The explanation of this phenomenon can be found in the electric field modification inside the non-equilibrium plasma because of an electron bunching that increases the number of electron-ion interactions. The magnetic field, in fact, modifies the electric field due to the charge separation between the clouds of fast electrons, many of which remain trapped in the magnetic hole, and slow ions, ejected from the ablated target; moreover it increases the number of electron-ion interactions producing higher charge states.

scholarly journals The magnetic-field strengths of accreting millisecond pulsars

2015 ◽  
Vol 452 (4) ◽  
pp. 3994-4012 ◽  
Author(s):  
Dipanjan Mukherjee ◽  
Peter Bult ◽  
Michiel van der Klis ◽  
Dipankar Bhattacharya
Keyword(s):  
Magnetic Field ◽  
Millisecond Pulsars ◽  
The Magnetic Field ◽  
Field Strengths

Investigation of DC Vacuum Arc Interruption Ability with Combined Axial and Radial Magnetic Field

2012 ◽  
Vol 516-517 ◽  
pp. 1791-1797 ◽  
Author(s):  
Mohmmad Al Dweikat ◽  
Yu Long Huang ◽  
Xiao Lin Shen ◽  
Wei Dong Liu
Keyword(s):  
Magnetic Field ◽  
Axial Magnetic Field ◽  
Vacuum Arc ◽  
Axial Component ◽  
Circuit Breakers ◽  
Radial Magnetic Field ◽  
Vacuum Interrupter ◽  
Magnetic Field Simulation ◽  
The Magnetic Field ◽  
Field Influence

DC Vacuum Circuit Breakers based arc control has been a major topic in the last few decades. Understanding vacuum arc (VA) gives the ability to improve vacuum circuit breakers capacity. In this paper, the interaction of a DC vacuum arc with a combined Axial-Radial magnetic field was investigated. The proposed system contains an external coil to produce axial magnetic field (AMF) across the vacuum chamber. The vacuum interrupter (VI) contacts were assumed to be untreated radial magnetic field (RMF) contacts. For this purpose, Finite Element Method (FEM) based Multiphysics simulation of the immerging magnetic field influence on the VA is presented. The simulation shown the ability of the presented system to deflect high DC vacuum arc, also reveals that the vacuum arc interruption capability increases with the rise of the axial component of the magnetic field. Simulation results shown that this method can be applied to improve the interruption capability of the VI.

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