Frequency effects of a rotating magnetic field on fluid flow in vertical cylinders

1997 ◽  
Author(s):  
Konstantin Mazuruk ◽  
Narayanan Ramachandran ◽  
Martin P. Volz ◽  
Donald C. Gillies
Keyword(s):  
Magnetic Field ◽  
Fluid Flow ◽  
Rotating Magnetic Field ◽  
Frequency Effects ◽  
Vertical Cylinders

Swirling Flow of Magnetic Fluid in Multi-Pole Rotating Magnetic Field

2003 ◽  
Author(s):  
Kenichi Kamioka ◽  
Ryuichiro Yamane
Keyword(s):  
Magnetic Field ◽  
Fluid Flow ◽  
Circular Cylinder ◽  
Phase Velocity ◽  
Magnetic Fluid ◽  
Swirling Flow ◽  
Peak Velocity ◽  
Rotating Magnetic Field ◽  
Outer Periphery ◽  
The Magnetic Field

The experiments are conducted on the magnetic fluid flow induced by the multi-pole rotating magnetic field in a circular cylinder. The numbers of poles are two, four, six, eight and twelve. The applied electric current and frequency are 2∼6 A and 20∼60 Hz, respectively. The peak velocity of the flow increases with the increase in the strength and the phase velocity of the magnetic field. As the increase in the number of poles, the flow shifts to the outer periphery.

Effect of Rotating Magnetic Field on Microstructure Evolution of Pb-Bi Alloys

2011 ◽  
Vol 311-313 ◽  
pp. 600-608
Author(s):  
Zhao Chen ◽  
Xiao Li Wen ◽  
Chang Le Chen
Keyword(s):  
Magnetic Field ◽  
Fluid Flow ◽  
Microstructure Evolution ◽  
Solidification Process ◽  
Nucleation And Growth ◽  
Primary Phase ◽  
Rotating Magnetic Field ◽  
Growth Behaviour ◽  
Solidification Behaviour ◽  
40 Hz

Solidification behaviour of Pb-Bi alloys under rotating magnetic field (RMF) was investigated experimentally to understand the effect of the frequency of RMF on the nucleation and growth behaviour. It was found that, as the increase of the rotating frequency, the grains are fragmented and refined gradually until a transition from columnar to equiaxed microstructures happens at a rotating frequency of 40 Hz. Moreover, the Bi concentration of the primary phase decreases and macrosegregation is eliminated effectively with RMF. These are due to the effect of RMF on the nucleation, growth and fluid flow in the solidification process.

On fluid flow induced by a rotating magnetic field

1965 ◽  
Vol 22 (3) ◽  
pp. 521-528 ◽  
Author(s):  
H. K. Moffatt
Keyword(s):  
Magnetic Field ◽  
Fluid Flow ◽  
Transverse Magnetic ◽  
Rotating Magnetic Field ◽  
Cylindrical Container ◽  
General Shape ◽  
Electrically Conducting ◽  
Axis Parallel ◽  
Induced Currents ◽  
The Stability

The interior of an insulating cylindrical container is supposed filled with an incompressible, electrically conducting, viscous fluid. An externally applied magnetic field is caused to rotate uniformly about an axis parallel to the cylinder generators (by applying two alternating components out of phase at right angles). Induced currents in the fluid give rise to a Lorentz force which drives a velocity field, which in general may have a steady and a fluctuating component. The particular case of a circular cylindrical container in a transverse magnetic field is studied in detail. Under certain reasonable assumptions, the resulting flow is shown to have only the steady component, and the distribution of this component is determined. Some conjectures are offered about the stability of this flow and about the corresponding flows in cavities of general shape.

scholarly journals Microfluidic propulsion by the metachronal beating of magnetic artificial cilia: a numerical analysis

2011 ◽  
Vol 688 ◽  
pp. 44-65 ◽  
Author(s):  
S. N. Khaderi ◽  
J. M. J. den Toonder ◽  
P. R. Onck
Keyword(s):  
Magnetic Field ◽  
Fluid Flow ◽  
Phase Difference ◽  
Rotating Magnetic Field ◽  
Artificial Cilia ◽  
Discrete Nature ◽  
Recovery Stroke ◽  
Physical Interactions ◽  
Metachronal Waves ◽  
Considerable Enhancement

AbstractIn this work we study the effect of metachronal waves on the flow created by magnetically driven plate-like artificial cilia in microchannels using numerical simulations. The simulations are performed using a coupled magneto-mechanical solid–fluid computational model that captures the physical interactions between the fluid flow, ciliary deformation and applied magnetic field. When a rotating magnetic field is applied to super-paramagnetic artificial cilia, they mimic the asymmetric motion of natural cilia, consisting of an effective and recovery stroke. When a phase difference is prescribed between neighbouring cilia, metachronal waves develop. Due to the discrete nature of the cilia, the metachronal waves change direction when the phase difference becomes sufficiently large, resulting in antiplectic as well as symplectic metachrony. We show that the fluid flow created by the artificial cilia is significantly enhanced in the presence of metachronal waves and that the fluid flow becomes unidirectional. Antiplectic metachrony is observed to lead to a considerable enhancement in flow compared to symplectic metachrony, when the cilia spacing is small. Obstruction of flow in the direction of the effective stroke for the case of symplectic metachrony was found to be the key mechanism that governs this effect.

scholarly journals Effect of Rotating Magnetic Field on Microstructure in AlCuSi Alloys

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1804
Author(s):  
Piotr Mikolajczak
Keyword(s):  
Magnetic Field ◽  
Fluid Flow ◽  
Temperature Gradient ◽  
Phase Diagrams ◽  
Forced Convection ◽  
Rotating Magnetic Field ◽  
Electromagnetic Stirring ◽  
Number Density ◽  
Calphad Technique ◽  
Almost All

The solidification of AlCuSi alloys with Mn and Fe was studied by rotating a magnetic field to understand the effect of melt flow. The specimens solidified with a forced convection, low cooling rate and low temperature gradient. Electromagnetic stirring generated by an electric coil around the specimens caused a transformation from equiaxed dendritic to rosette morphology, occasionally with spheroids and minor dendrites. The transformation was quantitatively observed with a specific surface Sv, that decreased for almost all alloys and marked the flow effect on α-Al. The computer coupling of phase diagrams and thermochemistry (CALPHAD) technique was applied for the calculation of phase diagrams and property diagrams. Forced convection decreased secondary dendrite arm spacing λ2 in almost all alloys, while it increased slightly in one studied alloy. The length of detrimental β-Al5FeSi phases decreased in the alloy, where β starts to precipitate in the presence of α-Al, while increasing in alloys where β starts as first and grows in the fully liquid melt. The average overall dimension of the Mn-rich phases increased in almost all alloys, and the number density decreased under flow. The modification of spacing for AlSi-eutectics and Al2Cu was analyzed. It was found that the occurrence of Al2Cu does not influence the fluid flow and vice versa.

THE LINEAR NON-IRON INDUCTOR WITH ROTATING MAGNETIC FIELD

2018 ◽  
Vol 2018 (49) ◽  
pp. 39-50
Author(s):  
О. Karlov ◽  
◽  
I. Kondratenko ◽  
R. Kryshchuk ◽  
A. Rashchepkin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Rotating Magnetic Field
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