A Coupled System of a Magnet and Magnetic Fluid in a U-Tube under Reciprocating Traveling Magnetic Field

2010 ◽  
Vol 670 ◽  
pp. 207-214 ◽  
Author(s):  
Yasushi Ido ◽  
Koichi Hayashi ◽  
Takahiro Kunitomo
Keyword(s):  
Magnetic Field ◽  
Magnetic Fluid ◽  
Vibration Mode ◽  
Low Frequency ◽  
Coupled System ◽  
The Other ◽  
Reciprocating Motion ◽  
Vibration Properties ◽  
Short Cylinder ◽  
Traveling Magnetic Field

A coupled system of a magnet and magnetic fluid is used as a piston in a U-tube. Applying reciprocating travelling magnetic field produces reciprocating motion of the coupled system. In this study, vibration properties of the coupled system are investigated experimentally. Three types of vibration mode of the coupled system appear and the mode depends on the frequency and intensity of travelling magnetic field and the shape of the magnet. Basically the coupled system follows the travelling magnetic field in the range of low frequency, while the system cannot follow the travelling field when the frequency of the travelling magnetic field is high. However, when the magnet is sphere or short cylinder, the other type of vibration appears in the range of low frequency and the coupled system intermittently tracks the travelling magnetic field.

scholarly journals Numerical Simulation Analysis and Experimental Research on Damping Performance of a Novel Magnetic Fluid Damper

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Wenrong Yang ◽  
Dejie Wei ◽  
Jianzheng Su ◽  
Xiaorui Yang ◽  
Qingxin Yang
Keyword(s):  
Magnetic Field ◽  
Magnetic Fluid ◽  
Simulation Analysis ◽  
Damping Ratio ◽  
Low Frequency ◽  
Operating Characteristics ◽  
Damping Force ◽  
Rolling Ball ◽  
High Rise ◽  
Field Coupling

Considering the low-frequency and large-amplitude vibration characteristics of the high-rise structure, a tuned magnetic fluid rolling-ball damper is proposed to suppress the vibration of the structure. By adjusting the external magnetic field to control the natural rolling frequency of the ball, the purpose of tuning vibration reduction is achieved. Firstly, the working principle of the damper is theoretically analysed, a three-dimensional (3D) magnetic-fluid-solid multiphysical field coupling mathematical model of the damper is established and the governing equations of multiphysical field coupling are derived. Secondly, the magnetic field distribution and operating characteristics of the damper are simulated and analysed. Finally, the effectiveness of the model is verified by experiments, and the damping performance of the damper with two kinds of magnetic fluid is tested and compared. The results show that the magnetic-fluid-solid multiphysical field coupling model can accurately simulate the working characteristics of the damper. The maximum damping force of the damper is about 12% of the elastic force of the structure, which can increase the damping ratio of the structure by about two times, effectively reduce the vibration response time, and suppress the vibration of the high-rise structure.

SPIN–LATTICE INTERACTION EXPERIMENTS ON COLOR CENTERS IN QUARTZ

1964 ◽  
Vol 42 (4) ◽  
pp. 595-607 ◽  
Author(s):  
A. L. Taylor ◽  
G. W. Farnell
Keyword(s):  
Magnetic Field ◽  
Dielectric Loss ◽  
Low Frequency ◽  
The Other ◽  
Color Centers ◽  
Resonance Signal ◽  
Spin Lattice ◽  
Resonance Frequencies ◽  
Spin Resonance ◽  
The Magnetic Field

The paramagnetism of the color centers in smoky quartz is caused by the electron which is missing from a nonbonding oxygen orbital near an aluminum impurity. The effects produced by externally introduced microwave phonons on the spin-resonance signal from these color centers have been studied in detail as a function of the relative phonon and spin-resonance frequencies, the phonon power, the spectrometer power, the magnetic field angle, and the phonon polarization. As has been noted previously, these interactions do not conform with those observed in other paramagnetic crystals. Effects of an applied electric field on the resonance lines and various further experiments on the color centers in smoky quartz are reported; two in particular suggest that the "hole", the missing electron, makes thermally excited transitions between two different sites adjacent to a given impurity atom. One of the experiments is a measurement of the cross relaxation which takes place between the various lines of the spectrum, while the other is a measurement of the low-frequency dielectric loss found at liquid helium temperatures. An attempt is made to discuss the spin-phonon results in terms of such transitions for the holes.

Magnetic Fluid Layer on a Cylinder in a Traveling Magnetic Field

2006 ◽  
Vol 220 (1_2006) ◽  
pp. 117-124 ◽  
Author(s):  
Klaus Zimmermann ◽  
I. Zeidis ◽  
V.A. Naletova ◽  
V.A. Turkov ◽  
V. E. Bachurin
Keyword(s):  
Magnetic Field ◽  
Magnetic Fluid ◽  
Fluid Layer ◽  
Traveling Magnetic Field

Research on the low-frequency pressure generator based on magnetic fluid

2019 ◽  
Vol 33 (16) ◽  
pp. 1950173 ◽  
Author(s):  
Wenrong Yang ◽  
Yao Zhai ◽  
Xiaorui Yang
Keyword(s):  
Magnetic Field ◽  
Magnetic Fluid ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Magnetic Core ◽  
Input Current ◽  
Manufacturing Cost ◽  
Solenoid Coil ◽  
Output Pressure ◽  
Pressure Generator

To solve the problems that the existing pressure generators require high mechanical excitation frequency, need large manufacturing cost and are hard to control, a kind of pressure generator with low-frequency based on magnetic fluid is proposed in this paper. Magnetic fluid possesses the advantages of both magnetism of solid magnetic material and fluidity of liquid. The first-order buoyancy of magnetic fluid changes with low frequency alternating magnetic field. Based on this, the superimposed magnetic field is generated by electrifying the conical solenoid coil connected with the long solenoid coil with magnetic core in parallel. Magnetic field and magnetic force in the model are analyzed, then the relationship between input current and output pressure is calculated. In addition, the experimental platform is built and the performance of the device is tested. The result shows that the pressure generator can produce the corresponding pressure signal according to the input current.

Sign in / Sign up

Export Citation Format

Share Document