Numerical Study of the Role of Magnetic Field Ramping Rate on the Structure Formation in Magnetorheological Fluids

1999 ◽  
Vol 13 (14n16) ◽  
pp. 2060-2067 ◽  
Author(s):  
M. Mohebi ◽  
N. Jamasbi ◽  
G. A. Flores ◽  
Jing Liu
Keyword(s):  
Magnetic Field ◽  
Molecular Dynamics ◽  
Applied Field ◽  
Numerical Study ◽  
Dynamics Model ◽  
Structural Formation ◽  
Mr Fluids ◽  
Maximum Range ◽  
Simulation Results

A molecular dynamics model is presented to understand the structural formation of MR fluids by including the thermal motion of the particles. The simulation results indicate that the complexity of the lateral pattern as viewed in the direction of the applied field increases with the rate of the application of external magnetic field. We have also found that the maximum range for attractive interaction (escape distance) for two initially straight chains increases with temperature. These results are relevant to understand the mechanisms and conditions for the formation of labyrinthine and columnar patterns found in MR fluids.

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.

scholarly journals The role of the Heisenberg principle in constrained molecular dynamics model

2019 ◽  
Vol 28 (06) ◽  
pp. 1950039
Author(s):  
K. Wang ◽  
A. Bonasera ◽  
H. Zheng ◽  
G. Q. Zhang ◽  
Y. G. Ma ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Pauli Principle ◽  
Binding Energies ◽  
Light Nuclei ◽  
Scattering Data ◽  
Collision Term ◽  
Dynamics Model ◽  
Heisenberg Principle ◽  
The One

We implement the Heisenberg principle into the Constrained Molecular Dynamics model with a similar approach to the Pauli principle using the one-body occupation probability [Formula: see text]. Results of the modified and the original model with comparisons to data are given. The binding energies and the radii of light nuclei obtained with the modified model are more consistent with the experimental data than the original one. The collision term and the density distribution are tested through a comparison to p+[Formula: see text]C elastic scattering data. Some simulations for fragmentation and superheavy nuclei production are also discussed.

scholarly journals Role of Magnetorheological Fluids and Elastomers in Today’s World

2017 ◽  
Vol 11 (4) ◽  
pp. 267-274 ◽  
Author(s):  
Paweł Skalski ◽  
Klaudia Kalita
Keyword(s):  
Magnetic Field ◽  
Automotive Industry ◽  
Smart Materials ◽  
Magnetorheological Fluids ◽  
Magnetorheological Elastomer ◽  
Shock Absorbers ◽  
Damping Control ◽  
Mr Fluids ◽  
High Tension

AbstractThis paper explains the role of magnetorheological fluids and elastomers in today’s world. A review of applications of magnetorheological fluids and elastomers in devices and machines is presented. Magnetorheological fluids and elastomers belong to the smart materials family. Properties of magnetorheological fluids and elastomers can be controlled by a magnetic field. Compared with magnetorheological fluids, magnetorheological elastomers overcome the problems accompanying applications of MR fluids, such as sedimentation, sealing issues and environmental contamination. Magnetorheological fluids and elastomers, due to their ability of dampening vibrations in the presence of a controlled magnetic field, have great potential present and future applications in transport. Magnetorheological fluids are used e.g. dampers, shock absorbers, clutches and brakes. Magnetorheological dampers and magnetorheological shock absorbers are applied e.g. in damping control, in the operation of buildings and bridges, as well as in damping of high-tension wires. In the automotive industry, new solutions involving magnetorheological elastomer are increasingly patented e.g. adaptive system of energy absorption, system of magnetically dissociable [hooks/detents/grips], an vibration reduction system of the car’s drive shaft. The application of magnetorheological elastomer in the aviation structure is presented as well.

Molecular Dynamics Simulations of Water, Silica, and Aqueous Mixtures in Bulk and Confinement

2018 ◽  
Vol 232 (7-8) ◽  
pp. 1187-1225 ◽  
Author(s):  
Julian Geske ◽  
Michael Harrach ◽  
Lotta Heckmann ◽  
Robin Horstmann ◽  
Felix Klameth ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bond ◽  
Molecular Dynamics Simulations ◽  
Aqueous Mixtures ◽  
Simulation Data ◽  
Hydrogen Bond Networks ◽  
Simulation Results ◽  
Dynamics Simulations ◽  
Anomalies Of Water

Abstract Aqueous systems are omnipresent in nature and technology. They show complex behaviors, which often originate in the existence of hydrogen-bond networks. Prominent examples are the anomalies of water and the non-ideal behaviors of aqueous solutions. The phenomenology becomes even richer when aqueous liquids are subject to confinement. To this day, many properties of water and its mixtures, in particular, under confinement, are not understood. In recent years, molecular dynamics simulations developed into a powerful tool to improve our knowledge in this field. Here, our simulation results for water and aqueous mixtures in the bulk and in various confinements are reviewed and some new simulation data are added to improve our knowledge about the role of interfaces. Moreover, findings for water are compared with results for silica, exploiting that both systems form tetrahedral networks.

Yield and Rheological Behaviors of Magnetorheological Fluids

2010 ◽  
Vol 97-101 ◽  
pp. 875-879
Author(s):  
Jian Min He ◽  
Jin Huang ◽  
Cheng Liu
Keyword(s):  
Magnetic Field ◽  
Yield Stress ◽  
Applied Magnetic Field ◽  
Applied Field ◽  
Shear Strain Rate ◽  
Bingham Model ◽  
Bingham Plastic ◽  
Rheological Behaviors ◽  
Mr Fluids ◽  
Magnetic Chain

Magnetorheological (MR) fluids are materials that respond to an applied magnetic field with the change of their yield and rheological behaviors. In this paper, the yield and rheological behaviors of MR fluids are discussed. Based on the microstructure of magnetic chain a theoretical model is developed to analyze the effect of an applied magnetic field on the yield stress of MR fluids. Bingham model is used to describe the rheological behaviors of MR fluids subject to an applied magnetic field. The results show that altering the strength of an applied field can control the yield stress of MR fluids. The shear stress increases as the strength of an applied magnetic field increases, and it hardly changes with the increase of shear strain rate. MR fluids exhibit Bingham plastic model.

Properties and Applications of Magnetorheological Fluids

1999 ◽  
Vol 604 ◽  
Author(s):  
M.R. Jolly
Keyword(s):  
Magnetic Field ◽  
Yield Stress ◽  
Applied Magnetic Field ◽  
Rheological Behavior ◽  
Applied Field ◽  
Mechanical Systems ◽  
Magnetorheological Fluids ◽  
Rapid Response ◽  
Basic Composition ◽  
Mr Fluids

AbstractMagnetorheological (MR) fluids are materials that respond to an applied magnetic field with a change in rheological behavior. Typically, this change is manifested by the development of a yield stress that monotonically increases with applied field. Interest in MR fluids derives from their ability to provide simple, quiet and rapid response interfaces between electronic controls and mechanical systems. In this paper, the basic composition and properties of example MR fluids are reviewed. Some contemporary applications of MR fluids are then discussed.

Large-scale magnetic field of the accretion disks of T Tauri stars

2018 ◽  
Vol 14 (S345) ◽  
pp. 297-298
Author(s):  
Alexander E. Dudorov ◽  
Sergey A. Khaibrakhmanov ◽  
Sergey Yu. Parfenov ◽  
Andrey M. Sobolev
Keyword(s):  
Magnetic Field ◽  
Accretion Disks ◽  
Large Scale ◽  
Young Stars ◽  
T Tauri ◽  
Ionization Structure ◽  
Large Scale Magnetic Field ◽  
Field Geometry ◽  
Simulation Results

AbstractThe large-scale magnetic field in the accretion disks of young stars is investigated. Main features of our magnetohydrodynamical (MHD) model of the accretion disks and typical simulation results are presented. We discuss the role of MHD effects, ionization structure, magnetic field geometry and strength of the accretion disks.

Control of Multiple Magnetic Micro Robots

2015 ◽  
Author(s):  
Denise Wong ◽  
Jeremy Wang ◽  
Edward Steager ◽  
Vijay Kumar
Keyword(s):  
Magnetic Field ◽  
Linear System ◽  
Applied Field ◽  
Dimensional System ◽  
One Dimensional ◽  
Electromagnetic Coils ◽  
Micro Robot ◽  
Simulation Results ◽  
Visual Feedback Control ◽  
The Magnetic Field

A magnetic micro robot is a microscopic magnet that is controlled by a system of electromagnetic coils that generate a magnetic field to manipulate the magnetic robot. A major challenge for manipulating multiple magnets at microscale is that the applied field affects the entire workspace, making it difficult to address individual magnets. In this paper, we propose a system where electromagnetic coils are close to the magnets being manipulated to exploit spatial non-uniformities in the magnetic field. Our model considers the magnetic field generated by the electromagnetic coils and the magnetic fields present from neighboring magnetic robots to generate the desired force on each magnet. This approach is demonstrated on a macroscopic, one-dimensional system with two magnets controlled by two electromagnets using visual feedback control. Additionally, simulation results for a linear system with three magnets and three electromagnets are shown. While demonstrated at the macroscale, our results suggest that our methods can be extended for microscale manipulation, where it is advantageous to control multiple identical magnets with global fields.

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