scholarly journals Simulations of the Behaviour of Steel Ferromagnetic Fibres Commonly Used in Concrete in a Magnetic Field

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 128
Author(s):  
Kateřina Nováková ◽  
Kristýna Carrera ◽  
Petr Konrád ◽  
Karel Künzel ◽  
Václav Papež ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Numerical Model ◽  
Fresh Concrete ◽  
Single Fibre ◽  
Magnetic Saturation ◽  
Experimental Setup ◽  
Fibre Reinforcement ◽  
Helmholtz Coils ◽  
Fibre Size ◽  
The Magnetic Field

The efficiency of fibre reinforcement in concrete can be drastically increased by orienting the fibres using a magnetic field. This orientation occurs immediately after pouring fresh concrete when the fibres can still move. The technique is most relevant for manufacturing prefabricated elements such as beams or columns. However, the parameters of such a field are not immediately apparent, as they depend on the specific fibre reaction to the magnetic field. In this study, a numerical model was created in ANSYS Maxwell to examine the mechanical torque acting on fibres placed in a magnetic field with varying parameters. The model consists of a single fibre placed between two Helmholtz coils. The simulations were verified with an experimental setup as well as theoretical relationships. Ten different fibre types, both straight and hook-ended, were examined. The developed model can be successfully used to study the behaviour of fibres in a magnetic field. The fibre size plays the most important role together with the magnetic saturation of the fibre material. Multiple fibres show significant interactions.

scholarly journals Extensional Magnetorheology as a Tool for Optimizing the Formulation of Ferrofluids in Oil-Spill Clean-Up Processes

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 597 ◽  
Author(s):  
José Hermenegildo García-Ortiz ◽  
Francisco José Galindo-Rosales
Keyword(s):  
Magnetic Field ◽  
Oil Spill ◽  
Particle Concentration ◽  
Flow Direction ◽  
Extensional Flow ◽  
Rheological Behaviour ◽  
Magnetic Saturation ◽  
Parallel Configuration ◽  
Thinning Process ◽  
The Magnetic Field

In this study, we propose a new way of optimising the formulation of ferrofluids for oil-spill clean-up processes, based on the rheological behaviour under extensional flow and magnetic fields. Different commercial ferrofluids (FFs), consisting of a set of six ferrofluids with different magnetic saturation and particle concentration, were characterised in a Capillary Break-Up Extensional Rheometer (CaBER) equipped with two magnetorheological cells that allow imposing a homogeneous and tunable magnetic field either parallel or perpendicular to the flow direction. The filament thinning process with different intensities and orientation of the magnetic field with respect to the flow direction was analysed, and the results showed that the perpendicular configuration did not have a significant effect on the behaviour of the ferrofluids, as in shear magnetorheometry. However, the parallel configuration allowed to determine that the formulation of ferrofluids for oil-spill cleaning processes should consist of a 4% vol concentration of magnetic nanoparticles with a magnetic saturation of M s > 20 mT.

Analysis and Experimental Study on Magnetic Fluid Seal Mechanism

2011 ◽  
Vol 492 ◽  
pp. 273-276 ◽  
Author(s):  
Hai Na Zhang ◽  
De Cai Li
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Field Distribution ◽  
Magnetic Fluid ◽  
Magnetic Field Distribution ◽  
Gas Flows ◽  
Experimental Setup ◽  
Pressure Transmission ◽  
The Magnetic Field ◽  
The Way

The authors put forward a new design of experimental setup in order to study the mechanism of magnetic fluid seal, and used Ansys to simulate the magnetic field distribution in the setup, the results prove its rationality. The experiment to study the way of pressure transmission has been done on the experimental setup. The experimental conclusion shows that pressure transmission is based on the recoverability of the magnetic fluid seal. When pressure exceeds the ability of the seal stage, there is a leak path in the magnetic fluid, and then the gas flows to the next stage, after that, the leak path disappears. Pressure transmits from one seal stage to the next one in this way.

scholarly journals Simulation of the magnetic field generated by square shape Helmholtz coils

2016 ◽  
Vol 40 (23-24) ◽  
pp. 9835-9847 ◽  
Author(s):  
Ronald Hurtado-Velasco ◽  
Jesus Gonzalez-Llorente
Keyword(s):  
Magnetic Field ◽  
Helmholtz Coils ◽  
The Magnetic Field

Finite Element Analysis of Thrust Bearing Magnetic Field in 22KW Spindle

2008 ◽  
Vol 392-394 ◽  
pp. 761-766 ◽  
Author(s):  
G.Q. Wu ◽  
J.L. Zhou ◽  
Xu Dong Zhang ◽  
Y.M. Zhang ◽  
Xiao Ni Chi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Thrust Bearing ◽  
System Structure ◽  
Magnetic Saturation ◽  
Element Analysis ◽  
Direction Control ◽  
And Performance ◽  
The Magnetic Field ◽  
Flux Leakage

There is a magnetic field inside thrust bearing. The magnetic field distribution is one of the key factors which decide the running state and performance. With the finite element of ANSYS software, the magnetic field of thrust bearing has been analyzed. The rule of changes between the magnetic field and the influencing factors has been discovered. The analysis shows that the direction of exciting current should be opposite other than identical. The greater the ratio of gap length between stator and rotor and working gap length is, the less magnetic field leakage is. The flux leakage of thrust bearing attains 37 percent when the ratio of the gap is 4.0. If the design of a complete machine is not proper, the flux leakage may attain 20 percent upwards through other gaps although that of the bearing itself is almost zero. Calculation of bearing capacity indicates that theoretical value is not exact due to its neglect of magnetic saturation and flux leakage, while FEM value comparably matches the real substance with considering the magnetic saturation and flux leakage. The research provides the theoretical basis for optimization of system structure and selection of current direction control.

scholarly journals Magnetic field computation and simulation of the coil systems using Comsol software

2018 ◽  
Vol 160 ◽  
pp. 01006 ◽  
Author(s):  
Ivan Zatonov ◽  
Pavel Baranov ◽  
Andrey Kolomeycev
Keyword(s):  
Magnetic Field ◽  
Axial Direction ◽  
Calibration System ◽  
Method Of Calculation ◽  
Helmholtz Coils ◽  
Magnetic Field Homogeneity ◽  
Different Types ◽  
Field Homogeneity ◽  
Magnetic Field Computation ◽  
The Magnetic Field

The article considers the calibration system computation with the inhomogeneity of magnetic field less than 0.1 %. Method of calculation is described. The numerical simulation using finite-element analyze was made for such system as: Helmholtz coils, improved Helmholtz coils, four and six coils system. Authors made the calculation of the magnetic field homogeneity toward axial direction. Based on procure results, authors analyzed magnetic field homogeneity and compared different types of coil systems.

scholarly journals Identification of the Structures for Low Reynolds Number Flow in the Strong Magnetic Field

Fluids ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 36 ◽  
Author(s):  
Łukasz Pleskacz ◽  
Elzbieta Fornalik-Wajs
Keyword(s):  
Magnetic Field ◽  
Reynolds Number ◽  
Numerical Model ◽  
Reynolds Numbers ◽  
Flow Structures ◽  
Low Reynolds Number Flow ◽  
Reynolds Number Flow ◽  
Number Flow ◽  
The Magnetic Field ◽  
Field Influence

Thermomagnetic convection is still a phenomenon which generates interest among researchers. The authors decided to focus their attention on the magnetic field influence on forced convection and analyze the extended Graetz–Brinkman problem. A numerical model based on a commonly available solver implemented with user-defined functions was used. The results exhibited the variety of possible flow structures depending on the dimensionless parameters, namely Prandtl and Reynolds numbers. Three flow structure classes were distinguished, and they provide a platform for further research.

scholarly journals Effect of Electromagnetic Field (EMF) and Electric Field (EF) on Some Behavior of Honeybees (Apis melliferaL.)

2019 ◽  
Author(s):  
Yaşar Erdoğan ◽  
Mahir Murat Cengiz
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Helmholtz Coils ◽  
Electro Magnetic Field ◽  
Sugar Syrup ◽  
The Earth ◽  
Rapid Spread ◽  
Electrical Devices ◽  
Electro Magnetic ◽  
The Magnetic Field

ABSTRACTGeomagnetic field can be used by different magnetoreception mechanisms, for navigation and orientation by honeybees. The present study analyzed the effects of magnetic field on honeybees. This study was carried out in 2017 at the Bayburt University Beekeeping Application Station. In this study, the effect of Electro Magnetic field (EMF) and electric field (EF) on the time of finding the source of food of honeybees and the time of staying there were determined. The honeybees behaviors were analyzed in the presence of external magnetic fields generated by Helmholtz coils equipment. The Electro Magnetic field values of the coils were fixed to 0 μT (90mV/m), 50 μT (118 mV/m), 100 μT (151 mV/m), 150 μT (211 mV/m), 200 μT (264 mV/m). Petri dishes filled with sugar syrup were placed in the center of the coils. According to the study, honeybees visited at most U1 (mean =21.0±17.89 bees) and at least U5 (mean =10.82±11.77 bees). Honeybees waited for the longest time in U1 (mean =35.27±6.97 seconds) and at least in U5 (mean =12.28±5.58 seconds). According to the results obtained from this first study showed that honeybees are highly affected by electromagnetic radiation and electric field.SummaryHoneybees uses the magnetic field of the earth to to determine their direction. Nowadays, the rapid spread of electrical devices and mobile towers leads to an increase in man-made EMF. This causes honeybees to lose their orientation and thus lose their hives.

scholarly journals Impact of Magnetic Field on Variation of Partial Discharges Parameters in the Insulation Model with a Distributed Defect

2020 ◽  
Vol 20 (4) ◽  
pp. 64-69
Keyword(s):  
Magnetic Field ◽  
Experimental Technique ◽  
Partial Discharges ◽  
Experimental Results ◽  
Alternating Magnetic Field ◽  
Data Series ◽  
Experimental Setup ◽  
Mathematical Methods ◽  
New Phase ◽  
The Magnetic Field

The paper presents the experimental results of studies into the influence of an alternating magnetic field on the changes in the partial discharges parameters in the model of insulation with a distributed defect. The studies were carried out on a developed experimental setup, isolation model and based on the author's experimental technique. The research confirms the influence of the magnetic field on changes in the amplitude, number of pulses and intensity of partial discharges in practice. The analysis of the obtained data series for the reliability of differences was carried out using mathematical methods. Based on the results of the analysis of the phase-distributed patterns of the occurrence of partial discharges, the repeated appearance of additional discharges in new phase windows under the additional action of an alternating magnetic field was established.

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