Liquid Metal Free Surface Motion Submerged in an AC Magnetic Field

2007 ◽  
Vol 561-565 ◽  
pp. 1071-1074
Author(s):  
Kazuhiko Iwai ◽  
Shigeo Asai
Keyword(s):  
Magnetic Field ◽  
Free Surface ◽  
Liquid Metal ◽  
Standing Wave ◽  
Skin Layer ◽  
Alternating Magnetic Field ◽  
Liquid Gallium ◽  
Field Frequency ◽  
Surface Motion ◽  
The Magnetic Field

Free surface motion of a liquid metal submerged in an alternating magnetic field has been examined. A copper vessel filled with a liquid gallium is set in a coil for the imposition of the alternating magnetic field. The alternating magnetic field penetrates into a liquid gallium only from an upper free surface because thickness of the copper vessel is larger than the electromagnetic skin layer of copper. Time variation of displacement of the standing wave loop excited on the free surface is detected by a laser level sensor. The standing wave was suppressed not only by intensification of the magnetic field magnitude but also increase of the magnetic field frequency.

Experimental study on liquid metal free surface flow under magnetic and electric field for nuclear fusion

2022 ◽  
Author(s):  
Xu Meng ◽  
Z H Wang ◽  
Dengke Zhang
Keyword(s):  
Magnetic Field ◽  
Free Surface ◽  
Liquid Metal ◽  
Electric Field ◽  
Liquid Film ◽  
Metal Flow ◽  
First Wall ◽  
Flowing Liquid ◽  
Liquid Metal Flow ◽  
The Magnetic Field

Abstract In the future application of nuclear fusion, the liquid metal flows are considered to be an attractive option of the first wall of the Tokamak which can effectively remove impurities and improve the confinement of plasma. Moreover, the flowing liquid metal can solve the problem of the corrosion of the solid first wall due to high thermal load and particle discharge. In the magnetic confinement fusion reactor, the liquid metal flow experiences strong magnetic and electric, fields from plasma. In the present paper, an experiment has been conducted to explore the influence of electric and magnetic fields on liquid metal flow. The direction of electric current is perpendicular to that of the magnetic field direction, and thus the Lorentz force is upward or downward. A laser profilometer (LP) based on the laser triangulation technique is used to measure the thickness of the liquid film of Galinstan. The phenomenon of the liquid column from the free surface is observed by the high-speed camera under various flow rates, intensities of magnetic field and electric field. Under a constant external magnetic field, the liquid column appears at the position of the incident current once the external current exceeds a critical value, which is inversely proportional to the magnetic field. The thickness of the flowing liquid film increases with the intensities of magnetic field, electric field, and Reynolds number. The thickness of the liquid film at the incident current position reaches a maximum value when the force is upward. The distribution of liquid metal in the channel presents a parabolic shape with high central and low marginal. Additionally, the splashing, i.e., the detachment of liquid metal is not observed in the present experiment, which suggests a higher critical current for splashing to occur.

scholarly journals Tumor therapy by fast moving magnetic nanoparticle under low-frequency alternating magnetic field

2015 ◽  
Vol 08 (02) ◽  
pp. 1550008 ◽  
Author(s):  
Yangyang Liu ◽  
Zhiyu Qian ◽  
Jianhua Yin ◽  
Xiao Wang
Keyword(s):  
Magnetic Field ◽  
Tumor Cells ◽  
Magnetic Nanoparticle ◽  
Tumor Therapy ◽  
Low Frequency ◽  
Alternating Magnetic Field ◽  
Nanoparticle Concentration ◽  
Field Frequency ◽  
A New Technique ◽  
The Magnetic Field

Magnetic nanoparticle plays an important role in biomedical engineering, especially in tumor therapy. In this paper, a new technique has been developed by using the rapid moving magnetic nanoparticle under a low-frequency alternating magnetic field (LFAMF) to kill tumor cells. The LFAMF system which was used to drive magnetic nanoparticles (MNPs) was setup with the magnetic field frequency and power range at ∼ 10–100 Hz and ∼ 10–200 mT, respectively. During the experiment, the LFAMF was adjusted at different frequencies and power levels. The experimental results show that the liver tumor cells (HepG2) mixed with MNPs (10 μg/mL) became partial fragments when exposed in the LFAMF with different frequencies (∼ 10–100 Hz) and power (∼ 10–200 mT), and the higher the frequency or the power, the more the tumor cells were killed at the same magnetic nanoparticle concentration. Conclusion: Tumor cells were effectively damaged by MNPs under LFAMF, which suggests that they had great potential to be applied in tumor therapy.

Magnetic Field Effect on the Natural Convection of a Liquid Metal in a Horizontal Cylinder

2013 ◽  
Author(s):  
Z. H. Wang ◽  
S. Yang ◽  
H. Chen
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Natural Convection ◽  
Liquid Metal ◽  
Horizontal Cylinder ◽  
Movement Direction ◽  
Liquid Gallium ◽  
Induced Current ◽  
Convection And Heat Transfer ◽  
The Magnetic Field

Magneto-hydrodynamic (MHD) effects are widely exploited in different industrial processes. MHD play an essential role in nuclear fusion, where it is involved in the behavior of the liquid metal alloys employed in some of the currently considered designs of tritium breeding blankets. Results of numerical simulations are presented for the natural convection of a liquid metal placed in a horizontal cylinder in the presence of a vertical magnetic field. When there is an additional magnetic field, an induced current is produced by the movement of the liquid metal in a magnetic field. Induced current and magnetic field interaction produced a Lorentz force which is opposite to the movement direction and inhibits the natural convection and heat transfer intensity. The numerical results show that the magnetic field has a observable effect at the heat transfer process of the liquid metal natural convection in a horizontal cylinder. An interesting effect of the magnetic field during the internal flow is the deceleration of the flow velocity for liquid Gallium. The magnetic field in the horizontal radial direction, which is perpendicular to the natural convection caused by the temperature gradient all the while, has the most significant influence on the natural convection, while the influence on the axial direction is comparatively weak in medium magnetic field. With the increase of the intensity of magnetic field, the inhibition is more obvious.

scholarly journals Instability of a plane conducting free surface submitted to an alternating magnetic field

1998 ◽  
Vol 375 ◽  
pp. 65-83 ◽  
Author(s):  
Y. FAUTRELLE ◽  
A. D. SNEYD
Keyword(s):  
Magnetic Field ◽  
Free Surface ◽  
Growth Rates ◽  
Critical Magnetic Field ◽  
Hill Equation ◽  
Alternating Magnetic Field ◽  
Time Averaging ◽  
Weak Formulation ◽  
Field Frequency ◽  
The Stability

This paper considers the stability of a horizontal liquid-metal free surface in the presence of a horizontal alternating magnetic field. A weak formulation is used to derive a generalized Mathieu–Hill equation for the evolution of surface perturbations. Previous studies which rely on time-averaging the electromagnetic force over one field cycle have predicted a generally weak instability, but we find much larger growth rates near the resonances, where the surface wave frequency is an integral multiple of the field frequency. The method can be extended to include viscous and ohmic damping; the former has little effect, while the latter damps all waves except those whose frequency is close to the field frequency. Growth rates can be closely approximated by simple algebraic formulae, as can the critical magnetic field strength for the onset of instability.

Open Localization in Micro LeadFrame Package Using Space Domain Reflectometry

2013 ◽  
Author(s):  
J. Gaudestad ◽  
V. Talanov ◽  
A. Orozco ◽  
M. Marchetti
Keyword(s):  
Magnetic Field ◽  
Radio Frequency ◽  
Standing Wave ◽  
High Resistance ◽  
Space Domain ◽  
The Past ◽  
Open Defects ◽  
Rf Electronics ◽  
Rf Signal ◽  
The Magnetic Field

Abstract In the past couple years, Space Domain Reflectometry (SDR) has become a mainstream method to locate open defects among the major semiconductor manufacturers. SDR injects a radio frequency (RF) signal into the open trace creating a standing wave with a node at the open location. The magnetic field generated by the standing wave is imaged with a SQUID sensor using RF electronics. In this paper, we show that SDR can be used to non-destructively locate high resistance failures in Micro LeadFrame Packages (MLP).

Методика практического восстановления параметров формы поверхностных двухмерных дефектов с учетом нелинейных свойств ферромагнетика

2021 ◽  
pp. 46-55
Author(s):  
А.В. Никитин ◽  
А.В. Михайлов ◽  
А.С. Петров ◽  
С.Э. Попов
Keyword(s):  
Magnetic Field ◽  
Free Surface ◽  
Numerical Experiments ◽  
Input Data ◽  
Metal Plate ◽  
Two Dimensional ◽  
Nonlinear Properties ◽  
Data Errors ◽  
The Magnetic Field

A technique for determining the depth and opening of a surface two-dimensional defect in a ferromagnet is presented, that is resistant to input data errors. Defects and magnetic transducers are located on opposite sides of the metal plate. The nonlinear properties of the ferromagnet are taken into account. The components of the magnetic field in the metal were reconstructed from the measured components of the magnetic field above the defect-free surface of the metal. As a result of numerical experiments, the limits of applicability of the method were obtained. The results of the technique have been verified experimentally.

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