Calculation of eddy-current-induced magnetic fields in vacuum interrupters with axial magnetic field contacts

1988 ◽  
Vol 24 (5) ◽  
pp. 2204-2214 ◽  
Author(s):  
B.-J. Paul
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Eddy Current ◽  
Axial Magnetic Field

Turbulence changes from magnetic fields in a stationary plasma

2010 ◽  
Vol 77 (4) ◽  
pp. 537-545 ◽  
Author(s):  
A. B. ALEXANDER ◽  
C. T. RAYNOR ◽  
D. L. WIGGINS ◽  
M. K. ROBINSON ◽  
C. C. AKPOVO ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Axial Magnetic Field ◽  
Turbulent Energy ◽  
Dominant Mode ◽  
Dc Glow Discharge ◽  
Turbulent Fluctuations ◽  
Stationary Plasma

AbstractWhen the krypton plasma in a DC glow discharge tube is exposed to an axial magnetic field, the turbulent energy and the characteristic dominant mode in the turbulent fluctuations are systematically and unexpectedly reduced with increasing magnetic field strength. When the index measuring the rate of transfer of energy through fluctuation scales is monitored, a lambda-like dependence on turbulent energy is routinely observed in all magnetic fields. From this, a critical turbulent energy is identified, which also decreases with increasing magnetic field strength.

Macro and Microstructural Effects of the Application of an Induced Axial Magnetic Field During the Deposition of Aluminum Weld Beads

2009 ◽  
Vol 1242 ◽  
Author(s):  
M. A. García ◽  
V. H. López M. ◽  
R. García H. ◽  
F. F. Curiel L. ◽  
R. R. Ambríz R.
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Magnetic Fields ◽  
Weld Metal ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Axial Magnetic Field ◽  
Grain Structure ◽  
Bead Geometry ◽  
External Power Source

ABSTRACTIn this work, aluminum weld beads were deposited on aluminum plates of commercial purity (12.7 mm thick), using an ER-5356 filler wire. The aim of the experiments was to assess the effects that yield the induction of an axial magnetic field (AMF) during the application of the weld beads using the direct current gas metal arc welding process (DC-GMAW). An external power source was use to induce magnetic fields between 0 to 28 mT. The effects of the magnetic fields were assessed in terms of the macrostructural features of the deposits, morphology of the grain structure, grain size and grain size distribution in the weld metal. Macrostructural characteristics of the weld beads revealed that increasing the intensity of the magnetic induction to produce a magnetic field above 14 mT, leads to a significant loss of feeding material and there is a tendency of the deposits to increase their width and reduce penetration. Perturbation of the weld pool induced by the application of the AMF noticeably modified the grain structure in the weld metal. In particular, for the intensities of 5 and 14 mT, columnar growth was essentially non-existent. Grain size distribution plots showed, generally speaking, that the use of magnetic fields is an efficient method to produce homogeneous grain structures within the weld metal. Finite element analysis was used to explain the weld bead geometry with the intensity of the magnetic field.

Axial magnetic field contacts with nonuniform distributed axial magnetic fields

2003 ◽  
Vol 31 (2) ◽  
pp. 289-294 ◽  
Author(s):  
Zongqian Shi ◽  
Shenli Jia ◽  
Jun Fu ◽  
Zheng Wang
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Axial Magnetic Field

Improvement of UNS S32205 Duplex Welds by GMAW and Controlled Magnetic Field for Offshore Pipelines and Flowlines Applications

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
M. Salazar ◽  
R. García ◽  
V. H. López ◽  
R. Galván-Martínez ◽  
A. Contreras
Keyword(s):  
Magnetic Field ◽  
Corrosion Resistance ◽  
Magnetic Fields ◽  
Impact Toughness ◽  
Axial Magnetic Field ◽  
Gas Metal Arc Welding ◽  
Tensile Tests ◽  
Offshore Pipelines ◽  
Metal Arc Welding ◽  
Different Temperatures

Mechanical properties and corrosion resistance of UNS S32205 duplex stainless steel (DSS) welds obtained under the application of controlled magnetic fields were evaluated in the context of offshore pipelines and flowlines applications. Tensile tests, impact toughness, and hardness measurements were performed. Corrosion behavior was evaluated by linear polarization resistance (LPR) and potentiodynamic polarization curves (PCs) using a synthetic seawater solution at different temperatures. An improvement in tensile strength, impact toughness, and corrosion resistance was observed with the application of magnetic fields during welding. This effect is attributed to the refinement in the microstructure of the weld metal along with the suppression of detrimental intermetallic tertiary phases. Applying an axial magnetic field of 3 mT during DSS welding by the gas metal arc welding (GMAW) process is a potential technique for improving the performance of offshore pipeline welds and may be implemented in both, double-sided single pass and single-sided multipass butt joints.

Behavior of NiMnGa Under Dynamic Magnetic Fields Considering Magnetic Diffusion and Eddy Current Power Loss

2007 ◽  
Author(s):  
Xiang Wang ◽  
Marcelo J. Dapino
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Eddy Current ◽  
Volume Fraction ◽  
Constitutive Models ◽  
Skin Depth ◽  
Restoring Force ◽  
Magnetic Diffusion ◽  
The Third ◽  
Variant System

Prior experimental measurements by the authors demonstrated large reversible strains of up to –0.41% along the [001] crystal direction of a cylindrical Ni50Mn28.7Ga21.3 rod driven with a magnetic field along the same direction and no external restoring force. This represents an unusual configuration which can lead to solenoid transducers with enhanced energy density and bandwidth relative to standard electromagnet devices. Although a number of constitutive models have been developed which quantify magnetic field induced strain (MFIS) in these materials, models incorporating both the MFIS and transducer dynamics are scarce. This paper presents a transducer model that is built in three steps. In the first step, classic thermodynamics is used to calculate the volume fraction ξ of an ideal two-variant system as a function of magnetic fields and stresses. Bulk strains are then calculated through stochastic homogenization of the volume fraction. The transducer dynamics are quantified in the third step through calculation of magnetic diffusion in the sample, eddy current losses, and skin depth effects. The strain output is quantified at various magnetic field frequencies.

scholarly journals Gas–puff Z pinches with strong axial magnetic fields

1987 ◽  
Vol 5 (4) ◽  
pp. 699-706 ◽  
Author(s):  
F. S. Felber ◽  
F. J. Wessel ◽  
N. C. Wild ◽  
H. U. Rahman ◽  
A. Fisher ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Inertial Confinement Fusion ◽  
Scaling Laws ◽  
Axial Magnetic Field ◽  
Argon Laser ◽  
Nitrogen Laser ◽  
Inertial Confinement ◽  
X Ray ◽  
Confinement Fusion

Ultrahigh axial magnetic fields have been compressed and measured in a gas-puff Z pinch. A 0·5-MA, 2–cm-radius annular gas-puff Z pinch with a 3-minute repetition rate was imploded radially onto an axial seed field, causing the field to compress. Axial magnetic field compressions up to 180 and peak magnetic fields up to 1·6 MG were measured. Faraday rotation of an argon laser (515·4 nm) in a quartz fiber on axis was the principal magnetic field diagnostic. Other diagnostics included a nitrogen laser interferometer, x-ray diodes, and magnetic field probes.The magnetic field compression results are consistent with simple snowplow and self-similar analytic models, which are presented. The axial magnetic fields strongly affect the Z pinch dynamics. Even small axial fields help stabilize the pinches, some of which exhibit several stable radial bounces during a current pulse.The method of compressing axial fields in a gas-puff Z pinch is extrapolable to the order of 100 MG. Scaling laws are presented. Potential applications of ultrahigh axial fields in Z pinches are discussed for x-ray lasers, inertial confinement fusion, and collimated sources of gamma radiation.

scholarly journals Linear stability of thermocapillary convection in cylindrical liquid bridges under axial magnetic fields

1999 ◽  
Vol 394 ◽  
pp. 281-302 ◽  
Author(s):  
M. PRANGE ◽  
M. WANSCHURA ◽  
H. C. KUHLMANN ◽  
H. J. RATH
Keyword(s):  
Magnetic Field ◽  
Free Surface ◽  
Magnetic Fields ◽  
Prandtl Number ◽  
Linear Stability ◽  
Thermocapillary Convection ◽  
Axial Magnetic Field ◽  
Unstable Mode ◽  
Linear Stability Theory ◽  
The Stability

The stability of axisymmetric steady thermocapillary convection of electrically conducting fluids in half-zones under the influence of a static axial magnetic field is investigated numerically by linear stability theory. In addition, the energy transfer between the basic state and a disturbance is considered in order to elucidate the mechanics of the most unstable mode. Axial magnetic fields cause a concentration of the thermocapillary flow near the free surface of the liquid bridge. For the low Prandtl number fluids considered, the most dangerous disturbance is a non-axisymmetric steady mode. It is found that axial magnetic fields act to stabilize the basic state. The stabilizing effect increases with the Prandtl number and decreases with the zone height, the heat transfer rate at the free surface and buoyancy when the heating is from below. The magnetic field also influences the azimuthal symmetry of the most unstable mode.

Effect of axial magnetic field tapering on whistler-pumped FEL amplifier in collective Raman regime operation

2018 ◽  
Vol 7 (4) ◽  
pp. 2044
Author(s):  
Ram Gopal ◽  
Pradip Kumar Jain ◽  
Pradip Kumar Jain
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Magnetic Fields ◽  
Plasma Density ◽  
Cyclotron Frequency ◽  
Axial Magnetic Field ◽  
Electron Cyclotron ◽  
Interaction Region ◽  
Background Plasma ◽  
Transfer Energy

The dispersion relation of the FEL Amplifiers is sensitive to the linear tapered strong axial magnetic fields, electron cyclotron frequency and plasma frequency of electrons. For the synchronism of the pumped frequency, it should be closed to electron cyclotron frequency which is resonantly enhanced the wiggler wave number that produces the amplifier radiation for higher frequency from sub millimeter wave to optical ranges. The guiding of radiation signal into the waveguide and charge neutralization phenomenon, the beam density should be greater than the background plasma density with tapered strong axial magnetic field. It is quite considerable that radiation signal slowed down at much higher background plasma density comparable to the density of beams and enhanced the instability growth rate also. In Raman Regime operation, the growth rate decreases as increases with operation frequency of the amplifier, however, the growth rate is larger in this regime. It is noted that as increases with background plasma density, the beat wave frequency of the Ponderomotive waves is increases thus the mechanism of background plasma density can serve for tenability of the higher frequencies. The tapering of the strong guided magnetic field is a crucial role for enhancing the efficiency of the net transfer energy as well as reduction of interaction region along the axis. It is observed that, an efficiency of the transfer energy enhanced by while the reduction along the interaction region of about with the variation of tapering in a strong axial guided magnetic fields.  

scholarly journals Experimental Investigations on the Effect of Axial Homogenous Magnetic Fields on Propagating Vortex Flow in the Taylor–Couette System

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4027
Author(s):  
Thomas Ilzig ◽  
Katharina Stöckel ◽  
Stefan Odenbach
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Vortex Flow ◽  
Axial Magnetic Field ◽  
Intermittent Flow ◽  
Experimental Investigations ◽  
Temporal Behavior ◽  
Flow State ◽  
Orbital Frequency ◽  
Taylor Couette

Experimental investigations of propagating vortex flow states (pV states) in a short Taylor–Couette system with asymmetric boundary conditions are presented. The flow state was established in a ferrofluid showing no magneto-viscous effect and was exposed to axial magnetic fields. It was found that the magnetic field led to a change in the spatial and temporal behavior of the pV state, indicating complex interactions between the flow field and magnetic field. A stepwise applied axial magnetic field destabilized the pV state, leading to an intermittent flow state. Gradually increasing the axial magnetic fields changed the temporal behavior of the regime. Up to magnetic field strengths of 20 kA/m, the orbital frequency, as a measure for the temporal periodicity, was increased with field strength.

Sign in / Sign up

Export Citation Format

Share Document