A New Concept of Multimode Magnetorheological Brake Design

This paper presents a magnetorheological (MR) brake design by using additional squeeze working mode to an existing conventional rotational shear. The MR brake was designed with consideration given to a new concept of braking mechanism with the help of magnetic simulation. Important parameters such as disc brake dimensions, clearance gap and electromagnetic coil configuration were taken into account when constructed the MR brake. Simulation results showed that the magnetic field strength was at best by having the magnetic coil beside the non-magnetic material, which was located at the end of the outer diameter. Meanwhile, the value of magnetic field was greater than when a small squeeze gap was applied. Eventually, the design will provide an opportunity to study and consequently understand on how the MR fluids react to such operating condition in order to be realized in the MR brake.

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Selection of Materials in Designing Magnetorheological Brake

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.663.700 ◽

2014 ◽

Vol 663 ◽

pp. 700-704

Author(s):

Lailatul Hamidah Hamdan ◽

Saiful Amri Mazlan ◽

Shamsul Sarip ◽

Hairi Zamzuri ◽

Mohd Azizi Abdul Rahman

Keyword(s):

Magnetic Field ◽

Magnetic Material ◽

Field Strength ◽

Magnetic Field Strength ◽

Advanced Technology ◽

Brake Disc ◽

Finite Elements Analysis ◽

Mr Fluid ◽

The Magnetic Field ◽

Selection Of

The braking system is among the most significant active safety systems in a vehicle application for preventing injuries and property damage. Whether for light or heavy vehicles, brakes are no longer a small issue whereas it becomes a crucial problem to maintain the safety and to avoid the unpredictable cases especially on the road. Advanced technology in automotive industry has produced a new coming design of Magnetorheological (MR) brake which a field change is triggered off by changing the current in the coils exciting the magnetic field. MR fluid is one of the members of smart material which applicable usage to achieve the standard of rotary high speed similar as the existing brake disc in hydraulic system. A new MR brake disc was proposed using the squeeze mode rather than only conventional mode at the upper and lower rotating rotor. Parameters that have been considered are the types of MR fluid, selection of magnetic material, non-magnetic material and coil configurations. Then a finite elements analysis was performed to analyse the result of magnetic circuit and magnetic field strength within the MR brake configuration. MRF-140CG has been selected to represent the fluid to enhance the maximum magnetic flux density. The results showed that AISI 1020 and Stainless Steel 316 meet the requirement of material selection of magnetic and non-magnetic. Indirectly, yield stress has been significant increase when the magnetic field strength rises at certain value. Therefore, intention on design innovation of MR brake is useful to efficient control by upgrading function of those parameters which has been presented.

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The Development of Permanent Strong Magnets and its Application in the Deironing of Kaolin

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.217-219.690 ◽

2012 ◽

Vol 217-219 ◽

pp. 690-694

Author(s):

Gui Wu Fu ◽

Jun Liu ◽

Yu Hua Wang

Keyword(s):

Magnetic Field ◽

Magnetic Material ◽

Field Strength ◽

Permanent Magnet ◽

Chemical Industry ◽

Soft Magnetic Material ◽

Soft Magnetic ◽

Permanent Magnetic Field ◽

Iron Mineral ◽

The Magnetic Field

This paper considered that putting the specialized soft magnetic material in the permanent magnetic field with a particular structure and the magnetic field strength can make it be magnetized, finally the surface of the soft magnetic material will produce twice strength than that of original permanent magnetic field. And we made a analysis for said phenomenon. We introduce d the deironing machines of permanent magnet strong magnet and high-gradient permanent magnet which are manufactured based on this principle. They can effectively remove the iron mineral of "kaolin" and its principles and structure is simple but it has the advantages of high efficiecy, energy saving, environmental protection. So it provides important references to chemical industry, ceramics and other industries which apply kaolin technologies.

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On the Configuration of the Magnetic Field of β CrB

International Astronomical Union Colloquium ◽

10.1017/s0252921100080933 ◽

1976 ◽

Vol 32 ◽

pp. 613-622

Author(s):

I.A. Aslanov ◽

Yu.S. Rustamov

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Radial Velocity ◽

Magnetic Field Strength ◽

Complex Shape ◽

Rotation Period ◽

Field Variation ◽

Magnetic Field Variation ◽

Secular Variations ◽

The Magnetic Field

SummaryMeasurements of the radial velocities and magnetic field strength of β CrB were carried out. It is shown that there is a variability with the rotation period different for various elements. The curve of the magnetic field variation measured from lines of 5 different elements: FeI, CrI, CrII, TiII, ScII and CaI has a complex shape specific for each element. This may be due to the presence of magnetic spots on the stellar surface. A comparison with the radial velocity curves suggests the presence of a least 4 spots of Ti and Cr coinciding with magnetic spots. A change of the magnetic field with optical depth is shown. The curve of the Heffvariation with the rotation period is given. A possibility of secular variations of the magnetic field is shown.

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Simulations of Switchback, Fragmentation and Sunspot Pair in δ-Sunspots during Magnetic Flux Emergence

Sensors ◽

10.3390/s21020586 ◽

2021 ◽

Vol 21 (2) ◽

pp. 586

Author(s):

Che-Jui Chang ◽

Jean-Fu Kiang

Keyword(s):

Magnetic Field ◽

Solar System ◽

Field Strength ◽

Magnetic Flux ◽

Initial Conditions ◽

Observation Data ◽

Flux Emergence ◽

Polarity Inversion ◽

Simulation Results ◽

Spot Type

Strong flares and coronal mass ejections (CMEs), launched from δ-sunspots, are the most catastrophic energy-releasing events in the solar system. The formations of δ-sunspots and relevant polarity inversion lines (PILs) are crucial for the understanding of flare eruptions and CMEs. In this work, the kink-stable, spot-spot-type δ-sunspots induced by flux emergence are simulated, under different subphotospheric initial conditions of magnetic field strength, radius, twist, and depth. The time evolution of various plasma variables of the δ-sunspots are simulated and compared with the observation data, including magnetic bipolar structures, relevant PILs, and temperature. The simulation results show that magnetic polarities display switchbacks at a certain stage and then split into numerous fragments. The simulated fragmentation phenomenon in some δ-sunspots may provide leads for future observations in the field.

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Effect of Magnetic Field on the Forced Convective Heat Transfer of Water–Ethylene Glycol-Based Fe3O4 and Fe3O4–MWCNT Nanofluids

Applied Sciences ◽

10.3390/app11104683 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4683

Author(s):

Areum Lee ◽

Chinnasamy Veerakumar ◽

Honghyun Cho

Keyword(s):

Magnetic Field ◽

Heat Transfer ◽

Heat Transfer Coefficient ◽

Field Strength ◽

Ethylene Glycol ◽

Convective Heat Transfer ◽

Convective Heat ◽

Hybrid Nanofluid ◽

Forced Convective Heat Transfer ◽

The Magnetic Field

This paper discusses the forced convective heat transfer characteristics of water–ethylene glycol (EG)-based Fe3O4 nanofluid and Fe3O4–MWCNT hybrid nanofluid under the effect of a magnetic field. The results indicated that the convective heat transfer coefficient of magnetic nanofluids increased with an increase in the strength of the magnetic field. When the magnetic field strength was varied from 0 to 750 G, the maximum convective heat transfer coefficients were observed for the 0.2 wt% Fe3O4 and 0.1 wt% Fe3O4–MWNCT nanofluids, and the improvements were approximately 2.78% and 3.23%, respectively. The average pressure drops for 0.2 wt% Fe3O4 and 0.2 wt% Fe3O4–MWNCT nanofluids increased by about 4.73% and 5.23%, respectively. Owing to the extensive aggregation of nanoparticles by the external magnetic field, the heat transfer coefficient of the 0.1 wt% Fe3O4–MWNCT hybrid nanofluid was 5% higher than that of the 0.2 wt% Fe3O4 nanofluid. Therefore, the convective heat transfer can be enhanced by the dispersion stability of the nanoparticles and optimization of the magnetic field strength.

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The effects of magnetic field strength on the properties of wind generated from hot accretion flow

Astronomy and Astrophysics ◽

10.1051/0004-6361/201832985 ◽

2018 ◽

Vol 615 ◽

pp. A35 ◽

Cited By ~ 10

Author(s):

De-Fu Bu ◽

Amin Mosallanezhad

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Pressure Gradient ◽

Magnetic Field Strength ◽

Magnetic Pressure ◽

Gas Pressure ◽

Accretion Flow ◽

Accretion Flows ◽

Black Hole Accretion ◽

The Magnetic Field

Context. Observations indicate that wind can be generated in hot accretion flow. Wind generated from weakly magnetized accretion flow has been studied. However, the properties of wind generated from strongly magnetized hot accretion flow have not been studied. Aims. In this paper, we study the properties of wind generated from both weakly and strongly magnetized accretion flow. We focus on how the magnetic field strength affects the wind properties. Methods. We solve steady-state two-dimensional magnetohydrodynamic equations of black hole accretion in the presence of a largescale magnetic field. We assume self-similarity in radial direction. The magnetic field is assumed to be evenly symmetric with the equatorial plane. Results. We find that wind exists in both weakly and strongly magnetized accretion flows. When the magnetic field is weak (magnetic pressure is more than two orders of magnitude smaller than gas pressure), wind is driven by gas pressure gradient and centrifugal forces. When the magnetic field is strong (magnetic pressure is slightly smaller than gas pressure), wind is driven by gas pressure gradient and magnetic pressure gradient forces. The power of wind in the strongly magnetized case is just slightly larger than that in the weakly magnetized case. The power of wind lies in a range PW ~ 10−4–10−3 Ṁinc2, with Ṁin and c being mass inflow rate and speed of light, respectively. The possible role of wind in active galactic nuclei feedback is briefly discussed.

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ORIENTATION DYNAMICS OF MAGNETORHEOLOGICAL FLUIDS SUBJECT TO ROTATING EXTERNAL FIELDS

International Journal of Modern Physics B ◽

10.1142/s0217979201005234 ◽

2001 ◽

Vol 15 (06n07) ◽

pp. 758-766 ◽

Cited By ~ 6

Author(s):

SONIA MELLE ◽

MIGUEL A. RUBIO ◽

GERALD G. FULLER

Keyword(s):

Magnetic Field ◽

Light Scattering ◽

Simple Model ◽

Critical Frequency ◽

Optical Methods ◽

Phase Lag ◽

Rotating Magnetic Fields ◽

Mr Fluids ◽

Small Angle Light Scattering ◽

The Magnetic Field

The formation and orientation of field-induced structures in magnetorheological (MR) fluids subject to rotating magnetic fields have been studied using two optical methods: scattering dichroism and small angle light scattering (SALS). The SALS patterns show how these chain-like aggregates follow the magnetic field with the same frequency but with a retarded phase angle for all the frequencies measured. Using scattering dichroism two different behaviors for both, dichroism and phase lag, are found below or above a critical frequency. Experimental results have been reproduced by a simple model considering the torques balance on the chain-like aggregates.

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Magnetorheological fluid based on amorphous Fe-Si-B alloy magnetic particles

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x211064329 ◽

2021 ◽

pp. 1045389X2110643

Author(s):

Chuncheng Yang ◽

Zhong Liu ◽

Xiangyu Pei ◽

Cuiling Jin ◽

Mengchun Yu ◽

...

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Rheological Property ◽

Magnetic Particles ◽

Annealing Treatment ◽

Magnetorheological Fluid ◽

The Stability ◽

The Magnetic Field ◽

Amorphous Particle ◽

Better Than

Magnetorheological fluids (MRFs) based on amorphous Fe-Si-B alloy magnetic particles were prepared. The influence of annealing treatment on stability and rheological property of MRFs was investigated. The saturation magnetization ( Ms) of amorphous Fe-Si-B particles after annealing at 550°C is 131.5 emu/g, which is higher than that of amorphous Fe-Si-B particles without annealing. Moreover, the stability of MRF with annealed amorphous Fe-Si-B particles is better than that of MRF without annealed amorphous Fe-Si-B particles. Stearic acid at 3 wt% was added to the MRF2 to enhance the fluid stability to greater than 90%. In addition, the rheological properties demonstrate that the prepared amorphous particle MRF shows relatively strong magnetic responsiveness, especially when the magnetic field strength reaches 365 kA/m. As the magnetic field intensified, the yield stress increased dramatically and followed the Herschel-Bulkley model.

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COMPARISON OF CARDIAC MAGNETIC FIELD DISTRIBUTIONS DURING DEPOLARIZATION AND REPOLARIZATION

International Journal of Bifurcation and Chaos ◽

10.1142/s0218127403008971 ◽

2003 ◽

Vol 13 (12) ◽

pp. 3783-3789 ◽

Cited By ~ 4

Author(s):

F. E. SMITH ◽

P. LANGLEY ◽

L. TRAHMS ◽

U. STEINHOFF ◽

J. P. BOURKE ◽

...

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Magnetic Field Strength ◽

Field Distribution ◽

Normal Subjects ◽

The Body ◽

Magnetic Field Distribution ◽

T Wave ◽

High Magnetic Field Strength ◽

The Magnetic Field

Multichannel magnetocardiography measures the magnetic field distribution of the human heart noninvasively from many sites over the body surface. Multichannel magnetocardiogram (MCG) analysis enables regional temporal differences in the distribution of cardiac magnetic field strength during depolarization and repolarization to be identified, allowing estimation of the global and local inhomogeneity of the cardiac activation process. The aim of this study was to compare the spatial distribution of cardiac magnetic field strength during ventricular depolarization and repolarization in both normal subjects and patients with cardiac abnormalities, obtaining amplitude measurements by magnetocardiography. MCGs were recorded at 49 sites over the heart from three normal subjects and two patients with inverted T-wave conditions. The magnetic field intensity during depolarization and repolarization was measured automatically for each channel and displayed spatially as contour maps. A Pearson correlation was used to determine the spatial relationship between the variables. For normal subjects, magnetic field strength maps during depolarization (R-wave) showed two asymmetric regions of magnetic field strength with a high positive value in the lower half of the chest and a high negative value above this. The regions of high R-wave amplitude corresponded spatially to concentrated asymmetric regions of high magnetic field strength during repolarization (T-wave). Pearson-r correlation coefficients of 0.7 (p<0.01), 0.8 (p<0.01) and 0.9 (p<0.01) were obtained from this analysis for the three normal subjects. A negative correlation coefficient of -0.7 (p<0.01) was obtained for one of the subjects with inverted T-wave abnormalities, suggesting similar but inverted magnetic field and current distributions to normal subjects. Even with the high correlation values in these four subjects, the MCG was able to identify differences in the distribution of magnetic field strength, with a shift in the T-wave relative to the R-wave. The measurement of cardiac magnetic field distribution during depolarization and repolarization of normal subjects and patients with clinical abnormalities should enable the improvement of theoretical models for the explanation of the cardiac depolarization and repolarization processes.

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