An Investigation of the Behaviour of Magnetorheological Fluids in the Rotary Shock-Absorber

2012 ◽  
Vol 628 ◽  
pp. 512-517 ◽  
Author(s):  
Sławomir Kciuk ◽  
Monika Kciuk ◽  
Roman Turczyn ◽  
Paweł Martynowicz
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Structure Formation ◽  
Internal Structure ◽  
Carbonyl Iron ◽  
Shock Absorber ◽  
Experimental Studies ◽  
Magnetorheological Fluids ◽  
Control Current

The main aim of the article was to present the investigation results of created megnetorheological fluids using carbonyl iron (CI) particles and analyse their behaviour in terms of the internal structure formation by a control of external magnetic field. Results of the experimental studies of a prototype magnetorheological rotary shock-absorber at various magnitudes of control current was presented in this paper.

Magnetorheological properties and polishing characteristics of silica-coated carbonyl iron magnetorheological fluid

2017 ◽  
Vol 29 (1) ◽  
pp. 137-146 ◽  
Author(s):  
Kwang Pyo Hong ◽  
Ki Hyeok Song ◽  
Myeong Woo Cho ◽  
Seung Hyuk Kwon ◽  
Hyoung Jin Choi
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Field Intensity ◽  
Carbonyl Iron ◽  
Material Removal ◽  
Magnetic Field Intensity ◽  
Magnetorheological Fluid ◽  
Wheel Speed ◽  
Magnetorheological Fluids ◽  
Experimental Conditions

While magnetorheological fluids can be used for ultra-precise polishing, for example, of advanced optical components, oxidation of metallic particles in water-based magnetorheological fluids causes irregular polishing behavior. In this study, carbonyl iron microspheres were initially coated with silica to prevent oxidation and were used to polish BK7 glass. In addition, their rheological and sedimentation characterizations were investigated. Material removal and surface roughness were analyzed to investigate the surface quality and optimal experimental conditions of polishing wheel speed and magnetic field intensity. The maximum material removal was 0.95 µm at 95.52 kA/m magnetic field intensity and 1854 mm/s wheel speed. A very fine surface roughness of 0.87 nm was achieved using the silica-coated magnetorheological fluid at 47.76 kA/m magnetic field intensity and 1854 mm/s wheel speed.

Study of Microwave Reflection Behaviour in Fe3O4 Magnetorheological Fluids

2011 ◽  
Vol 287-290 ◽  
pp. 2785-2788
Author(s):  
Nan Hui Yu ◽  
Ji Jun Fan
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
External Magnetic Field ◽  
Field Strength ◽  
Smart Materials ◽  
Particle Concentration ◽  
Critical Concentration ◽  
Microwave Frequency ◽  
Magnetorheological Fluids ◽  
Microwave Reflection

Owing to its unique properties and wide engineering applications, magnetorheological fluids (MRF) has become a hot study area in the field of smart materials. In this paper experimental study of the microwave reflection behavior in MRF was carried out. The results indicated that at the same frequency the microwave reflectivity of MRF decreased with the increasing of magnetic field strength; and with the particle concentration increasing, microwave reflectivity first increased, then decreased, there is a critical concentration of 15%. Under the same magnetic field, with the increasing of microwave frequency, it first decreased, there is a lowest point at 9.2GHz, and then it increased. Usually, it is considered that the change of internal structure of MRF under external magnetic field is the main reason for the regulation behavior of microwave reflectivity.

Temperature Behavior of Magnetorheological Fluids

2005 ◽  
Vol 15 (2) ◽  
pp. 116-121 ◽  
Author(s):  
F. Zschunke ◽  
R. Rivas ◽  
P.O. Brunn
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Fluid Flows ◽  
Magnetorheological Fluids ◽  
Fluid Viscosity ◽  
Damping Force ◽  
Friction Dampers ◽  
Fluid Behavior ◽  
Magnetorheological Effect ◽  
The Magnetic Field

AbstractMagnetorheological fluids (MRFs) show a high but reversible rise of the viscosity upon application of an external magnetic field. This effect can be utilized in controllable friction dampers where the MR fluid flows through a gap with a adjustable magnetic field. The change in the magnitude of the magnetic field leads to a change of the viscosity of the fluid which in turn effects the pressure drop in the system. So the damping force can be controlled by the magnitude of the external magnetic field. This energy dissipation leads to a rise of the damper temperature. For designing those dampers it is vital to know the influence of the geometry, which influences the magnetic field strength, as well as the flow properties and the temperature dependence of the magnetorheological effect. An approach to the solution of this problem is shown by using an Arrhenius relationship, where the fluid viscosity is a function of the shear rate, the magnetic field and the temperature. The aim of the here presented research is to show how the fluid behavior can be simply modeled for use in CFD codes to design dampers or other applications.

Internal structure modification and decay of hadrons in strong magnetic field

2015 ◽  
Vol 39 ◽  
pp. 1560114
Author(s):  
Peter Filip
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
External Magnetic Field ◽  
Internal Structure ◽  
Strong Magnetic Field ◽  
Structure Modification ◽  
Decay Channels ◽  
Enhanced Production ◽  
Decay Products ◽  
Sufficient Strength

We discuss the influence of external magnetic field on strong decays of [Formula: see text], [Formula: see text] and [Formula: see text] mesons. Due to increasing energy of [Formula: see text] Landau level of charged decay products, particular decay channels may become suppressed and isospin rules for strong decays can be violated. In the case of [Formula: see text] meson, enhanced production of photons and dileptons (with modified invariant mass) may occur. Similar considerations are applied to decays of [Formula: see text] baryon. We also suggest that static electromagnetic field of sufficient strength can modify the internal structure (wavefunction) of [Formula: see text] J/[Formula: see text] and [Formula: see text] mesons, and specific decay channels (e.g. CP — violating [Formula: see text]) can become enhanced.

Regulation Behavior of Microwave Reflectivity in Magnetorheological Fluids

2011 ◽  
Vol 413 ◽  
pp. 213-216
Author(s):  
Ji Jun Fan ◽  
Nan Hui Yu
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
External Magnetic Field ◽  
Field Strength ◽  
Internal Structure ◽  
Magnetic Field Strength ◽  
Particle Concentration ◽  
Microwave Frequency ◽  
Microwave Reflection ◽  
The Given

In this paper, experimental study of the microwave reflection behavior in MRF was carried out. The results showed that at the same frequency the microwave reflectivity of MRF decreased with the increasing of magnetic field strength; and with the increasing of particle concentration, microwave reflectivity decreased, monotonously. Under the given magnetic field, with the increasing of microwave frequency, it first decreased, there is a lowest point at 9.2GHz, and then it increased. Usually, it is considered that the change of internal structure of MRF under external magnetic field is the main reason for the regulation behavior of microwave reflectivity.

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