An Experimental Investigation of Magnetorheological (MR) Fluids under Quasi-Static Loadings

2011 ◽  
Vol 495 ◽  
pp. 285-288 ◽  
Author(s):  
Saiful Amri Mazlan ◽  
Izwan Ismail ◽  
Mohamad S. Fathi ◽  
Shuib Rambat ◽  
Samsol F. Anis
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Systematic Investigation ◽  
Test Equipment ◽  
Structure Transformation ◽  
Carrier Fluid ◽  
Mr Fluids ◽  
Three Stages ◽  
Particle Chains ◽  
The Magnetic Field

In our earlier work, test equipment has been designed, simulated and fabricated to perform experiment on MR fluids in squeeze mode. Preliminary results were gathered and presented for the purpose of validating the test equipment. Therefore, in this paper, a further systematic investigation of MR fluids in squeeze mode has been carried out. As a result, MR fluids experienced rheological changes in three stages during compression and tension. Fluid-particles separation phenomenon was the main caused for the unique behaviour of MR fluids. Particle chains depended on the structure transformation in which the carrier fluid movement can be controlled by changing the magnetic field strength.

Experimental Investigation of the Transient Behavior of MR Fluids

2011 ◽  
Author(s):  
Ju¨rgen Maas ◽  
Dirk Gu¨th
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Response Time ◽  
Dynamic Properties ◽  
Transient Behavior ◽  
Current Control ◽  
Large Signal ◽  
Carrier Fluid ◽  
Mr Fluids ◽  
The Magnetic Field

The transient behavior of MRF actuators is an important property for certain applications that is mainly affected by three delays, occurring from the dynamic properties of the coil current, the magnetic field and the torque generation by the MRF. In order to investigate the transient behavior of the generated torque with respect to the magnetic field, which is mainly affected by the motion of the MR particles in the carrier fluid, the mentioned response time of the electrical and magnetic domains must be in an appropriated ratio in comparison to the MRF response time to obtain reliable results by experiments. Therefore a special disc-type test actuator with outstanding dynamics is designed that minimizes the delays by the use of an ultrafast current control and a magnetic core made of soft ferrite material for preventing the effects of eddy currents. For the experimental investigation of the transient behavior of MR fluids, the small signal as well as the large signal behavior is analyzed for different test signals and load conditions of the actuator. Various results of the investigated transient behavior are shown finally for two different MR fluids featuring response times of about 1 ms for the fluid itself and switching times of about 4 ms for the MRF actuator.

Experimental Investigation into the Effect of a Magnetic Field on Magnetorheological Fluids under an Impact Load

2012 ◽  
Vol 721 ◽  
pp. 179-184
Author(s):  
Ahmad Isnikurniawan ◽  
Yoshitaka Moroka ◽  
Hiromichi Ohba ◽  
Tatsuo Sawada
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Qualitative Analysis ◽  
Apparent Viscosity ◽  
Impact Load ◽  
Magnetorheological Fluids ◽  
Mr Fluids ◽  
Experimental Apparatus ◽  
The Impact ◽  
The Magnetic Field

The apparent viscosity of magnetorheological (MR) fluids changes in the presence of a magnetic field. The stronger the magnetic field applied, the more the apparent viscosity increases. An increase in the apparent viscosity increases the restriction on the flow of MR fluids. In this study, we perform a qualitative analysis to investigate the effect of a magnetic field on MR fluids under an impact load. An experimental apparatus that consists of a drop-test tower was developed to simulate the impact load, and an MR fluid in a U-pipe was subjected to the impact load via a piston rod. In the experiment, we measured the displacement and velocity of the piston rod. On the basis of the results, the influence of a given magnetic field on the behavior of MR fluids under an impact load is discussed.

ORIENTATION DYNAMICS OF MAGNETORHEOLOGICAL FLUIDS SUBJECT TO ROTATING EXTERNAL FIELDS

2001 ◽  
Vol 15 (06n07) ◽  
pp. 758-766 ◽  
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.

scholarly journals Investigation of mixing time in liquid under influence of rotating magnetic field

2017 ◽  
Vol 38 (4) ◽  
pp. 555-565
Author(s):  
Alicja Przybył ◽  
Rafał Rakoczy ◽  
Maciej Konopacki ◽  
Marian Kordas ◽  
Radosław Drozd ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Reynolds Number ◽  
Mixing Time ◽  
Rotating Magnetic Field ◽  
Homogenization Time ◽  
Set Up ◽  
The Relationship ◽  
The Magnetic Field

Abstract The aim of the study was to present an experimental investigation of the influence of the RMF on mixing time. The obtained results suggest that the homogenization time for the tested experimental set-up depending on the frequency of the RMF can be worked out by means of the relationship between the dimensionless mixing time number and the Reynolds number. It was shown that the magnetic field can be applied successfully to mixing liquids.

Experiment Using a Magnetically Controlled Ferrofluid Flow in a Flatplate Laminar Flow System

2014 ◽  
Vol 896 ◽  
pp. 444-447
Author(s):  
Yi Hua Fan ◽  
Liao Yong Lou ◽  
Yu Ming Chen
Keyword(s):  
Magnetic Field ◽  
Laminar Flow ◽  
Magnetic Particles ◽  
Flow System ◽  
Experimental Results ◽  
Carrier Fluid ◽  
Field Coefficient ◽  
Coefficient Of Viscosity ◽  
Relationship Of ◽  
The Magnetic Field

The Phenomenon of a Magnetic Controlled Ferrofluid Flow in the Flat Plate Laminar Flow System is Discussed in this Paper. the Ferrofluid Flow is One Kind of Colloid Mixture, which is Composited by the Magnetic Particles, Carrier Fluid and Surfactant. its Motion is Followed the Fluid Dynamics and can be Controlled by a Magnetic Field. from the Theoretic Analysis and the Experimental Test, the Coefficient of Viscosity of the Ferrofluid Flow will be Affected by the Magnetic Field. Thus, an Experimental Rig is Built to Test the Influences of the Gap of the Plate and the Strength and Direction of the Magnetic Field for Several Ferrofluid Flows with Different Dividing Rates of Volume. Experimental Results Showed that the Coefficient of Viscosity of the Ferrofluid Flow is Almost Not Upgrading in a Wide Gap Condition by the Magnetic Field, but as the Gap is Smaller, the Coefficient of Viscosity will be Promoted Obviously. Furthermore, Enhancing the Magnetic Field, it will be Increase the Coefficient of Viscosity of the Ferrofluid Flow. from the Experimental Results, the Relationship of the Magnetic Field, Coefficient of Viscosity of Ferrofluid Flow and the Carrier Fluid can be Confirmed.

A New Concept of Multimode Magnetorheological Brake Design

2014 ◽  
Vol 605 ◽  
pp. 271-274 ◽  
Author(s):  
L.H. Hamdan ◽  
Saiful Amri Mazlan ◽  
S. Sarip ◽  
Hairi Zamzuri
Keyword(s):  
Magnetic Field ◽  
Magnetic Material ◽  
Field Strength ◽  
Outer Diameter ◽  
Disc Brake ◽  
Electromagnetic Coil ◽  
Mr Fluids ◽  
Simulation Results ◽  
The Magnetic Field ◽  
Rotational Shear

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.

Development and Verification of Viscoelasticity Measurement System of MR Fluids in Magnetic Field

2012 ◽  
Vol 721 ◽  
pp. 114-119 ◽  
Author(s):  
Yuta Enokizono ◽  
Takashi Todaka ◽  
Masato Enokizono
Keyword(s):  
Magnetic Field ◽  
Measurement System ◽  
High Speed ◽  
Uniform Magnetic Field ◽  
Precise Measurement ◽  
Mr Fluid ◽  
Knowledge Based ◽  
Mr Fluids ◽  
The Magnetic Field ◽  
Speed Response

MR (Magnetic Rheological) fluid is a kind of functional fluid, which can be hardened by impressing magnetic flux. MR fluid has the high speed response to the external magnetic field and a big yield stress in comparison with the ferrofluid. In recent years, various devices utilizing MR fluid have been developed. Such developments are enabled with knowledge based on measured viscoelastic properties of MR fluid. However, precise measurement to obtain effect of the magnetic field on viscoelasticity is very difficult. The difficulty exists in generating a uniform magnetic field and evaluating the effective magnetic field. Accurate measurements become possible by solving these problems. In this paper, we propose a new magneto-viscoelasticity measurement system of MR fluid, which can generate a uniform magnetic field.

An experimental investigation into the behaviour of a spherical plasma resonance probe in a magnetic field

1967 ◽  
Vol 1 (4) ◽  
pp. 451-462
Author(s):  
P. G. Davies
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Discharge Current ◽  
Plasma Source ◽  
Simplified Model ◽  
Main Peak ◽  
Electron Current ◽  
Plasma Probe ◽  
Spherical Plasma ◽  
The Magnetic Field

The rectified electron current to a non-magnetic and to a magnetic spherical plasma probe has been investigated as a function of the frequency of the applied alternating potential, the discharge current in the plasma source and the magnitude of the magnetic field produced by a Helmholtz coil pair. The frequency at the main peak in the rectified current was found to be always greater than the gyro- frequency and to lie within a range of frequency predicted by Crawford from an analysis of a simplified model. The results of this laboratory work have been applied to a rocket-borne experiment on resonance rectification previously carried out by R.S.R.S.

Design and Performance Analysis on MR-Shock Absorber

2014 ◽  
Vol 984-985 ◽  
pp. 648-655
Author(s):  
M.L. Brabin Nivas ◽  
T. Prabaharan ◽  
J. Libin ◽  
T. Bibin Jose
Keyword(s):  
Magnetic Field ◽  
Mr Damper ◽  
Fast Response ◽  
Damping Force ◽  
Clear Fluid ◽  
Carrier Fluid ◽  
Fluid Turbulence ◽  
Mr Fluids ◽  
And Performance ◽  
Magneto Rheological

Abst r a c t -Magneto rheological aqueous is an old advancing to the bazaar at top speed. Excellent appearance like fast response, simple interface amid electrical ability ascribe and automated ability output, and absolute controllability accomplish MRF technology adorable for abounding applications.The aim of this project is preparation of MR-fluids by using the different types of carrier fluid mixed with iron powder and stability and magnetic properties are analysed. Thesedimentation of iron particles can be reduced by using additives. The sedimentation can be analysed by boundary variation of the clear fluid to the fluid turbulence. The viscosity of smart fluid can be increased by varying the applied magnetic field.The performance of the MR-damper depends on the applied maximum magnetic field and the hydraulic circuit design. The MR-damper force by increasing the magnetic field can be analysed by sing the FEMM V4 Software.Damping force depends on the excitation of current and magnetic field.Key words: Rheological, magnetic field, damping force, FEMM, flux density

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