Possibilities of 3D numerical simulations of electromagnetic induction pumps with permanent magnets

2012 ◽  
Vol 48 (4) ◽  
pp. 623-636 ◽  
Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Bocheng Bao ◽  
Aihuang Hu ◽  
Han Bao ◽  
Quan Xu ◽  
Mo Chen ◽  
...  

Since the electrical activities of neurons are closely related to complex electrophysiological environment in neuronal system, a novel three-dimensional memristive Hindmarsh–Rose (HR) neuron model is presented in this paper to describe complex dynamics of neuronal activities with electromagnetic induction. The proposed memristive HR neuron model has no equilibrium point but can show hidden dynamical behaviors of coexisting asymmetric attractors, which has not been reported in the previous references for the HR neuron model. Mathematical model based numerical simulations for hidden coexisting asymmetric attractors are performed by bifurcation analyses, phase portraits, attraction basins, and dynamical maps, which just demonstrate the occurrence of complex dynamical behaviors of electrical activities in neuron with electromagnetic induction. Additionally, circuit breadboard based experimental results well confirm the numerical simulations.


2019 ◽  
Vol 5 (3) ◽  
Author(s):  
David Rot ◽  
Jakub Jiřinec

This article deals with issues arising during the design and production of a cold crucible (CC) for melting metals and alloys using electromagnetic induction. The article deals particularly with the results from tests and numerical simulations for designing the CC. The heat fluxes from different metals and their alloys to two different CCs and one calorimeter were measured during the tests. The required magnetohydrodynamic effects on the melted load were verified, and related (independent) electrical and thermal quantities were measured. The dependent electric parameters (R, L, Z) were measured on the inductor and on the primary side of the high frequency transformer. The experiments were numerically simulated first, and the experimental and simulated results were then compared. The final part of the article contains the final design of the CC. The final CC was tested for the transfer of energy from the inductor into a load placed inside the CC and the required magnetohydrodynamic effects on the melted load inside the CC were partly verified too.


2008 ◽  
Vol 575-578 ◽  
pp. 1376-1381 ◽  
Author(s):  
Chao Jun Yang ◽  
Quan Wen Li ◽  
Hong Liang Ma ◽  
Sheng Fa Jiang

A new-type of solid rotor asynchronous magnetic coupling which works on the principle of electromagnetic induction is researched by ourselves. This kind of asynchronous magnetic coupling can solve the problem effectively that the permanent magnets on its inner rotor is demagnetized if its temperature is too high, because its inner rotor need not the permanent magnets. in order to study the transmission capability of the new-type magnetic coupling, its magnetic field should be analyzed. Because of its magnetic field variety, it is extremely complicated and a precision result is difficult to be got by the analytic method of the magnetic field calculation. Here the software ANSYS FEM is used to analyze its magnetic field. And some formulas were deduced and used to calculate its torque. The experimental and calculational results indicate that this design is practicable.


Author(s):  
I. Bucenieks

In the next generation neutron sources the HLM (heavy liquid metals) such as lead, lead based eutectic alloys and mercury will be used both as spallation target material and simultaneously as the cooling liquid. In this aspect the design of safe and effective pumps for HLM recirculation at high pressure heads and big flow rates becomes important. For this purpose electromagnetic inductions pumps having no problems of hydraulic seals being in contact with liquid metal (electromagnetic forces in the liquid metal are induced by magnetic system located outside of the channel of pump) are more perspective from the point of view of their safety for operation at high temperature and radiation conditions in comparison with mechanical pumps. At the Institute of Physics of University of Latvia (IPUL) the design concept of electromagnetic induction pumps basing on the principle of rotating permanent magnets (PMP) have been developed. Such design concept of electromagnetic induction pumps has many advantages in comparison with traditionally used electromagnetic induction pumps basing on 3-phase linear flat or cylindrical inductors. The estimations of parameters of powerful pumps (such as overall dimensions of the active magnetic system, power of motor needed for pump drive, the efficiency of pump) for mercury for the developed by pump pressure heads in the range up to 10.0 bar and provided flow rates in the range up to 20 litres per second are demonstrated.


Author(s):  
Hartmut Brauer ◽  
Konstantin Porzig ◽  
Judith Mengelkamp ◽  
Matthias Carlstedt ◽  
Marek Ziolkowski ◽  
...  

Purpose – The purpose of this paper is to present a novel electromagnetic non-destructive evaluation technique, so called Lorentz force eddy current testing (LET). This method can be applied for the detection and reconstruction of defects lying deep inside a non-magnetic conducting material. Design/methodology/approach – In this paper the technique is described in general as well as its experimental realization. Besides that, numerical simulations are performed and compared to experimental data. Using the output data of measurements and simulations, an inverse calculation is performed in order to reconstruct the geometry of a defect by means of sophisticated optimization algorithms. Findings – The results show that measurement data and numerical simulations are in a good agreement. The applied inverse calculation methods allow to reconstruct the dimensions of the defect in a suitable accuracy. Originality/value – LET overcomes the frequency dependent skin-depth of traditional eddy current testing due to the use of permanent magnets and low to moderate magnetic Reynolds numbers (0.1-1). This facilitates the possibility to detect subsurface defects in conductive materials.


Author(s):  
Raja K. Mishra

The discovery of a new class of permanent magnets based on Nd2Fe14B phase in the last decade has led to intense research and development efforts aimed at commercial exploitation of the new alloy. The material can be prepared either by rapid solidification or by powder metallurgy techniques and the resulting microstructures are very different. This paper details the microstructure of Nd-Fe-B magnets produced by melt-spinning.In melt spinning, quench rate can be varied easily by changing the rate of rotation of the quench wheel. There is an optimum quench rate when the material shows maximum magnetic hardening. For faster or slower quench rates, both coercivity and maximum energy product of the material fall off. These results can be directly related to the changes in the microstructure of the melt-spun ribbon as a function of quench rate. Figure 1 shows the microstructure of (a) an overquenched and (b) an optimally quenched ribbon. In Fig. 1(a), the material is nearly amorphous, with small nuclei of Nd2Fe14B grains visible and in Fig. 1(b) the microstructure consists of equiaxed Nd2Fe14B grains surrounded by a thin noncrystalline Nd-rich phase. Fig. 1(c) shows an annular dark field image of the intergranular phase. Nd enrichment in this phase is shown in the EDX spectra in Fig. 2.


Author(s):  
Mahesh Chandramouli

Magnetization reversal in sintered Fe-Nd-B, a complex, multiphase material, occurs by nucleation and growth of reverse domains making the isolation of the ferromagnetic Fe14Nd2B grains by other nonmagnetic phases crucial. The magnets used in this study were slightly rich in Nd (in comparison to Fe14Nd2B) to promote the formation of Nd-oxides at multigrain junctions and incorporated Dy80Al20 as a liquid phase sintering addition. Dy has been shown to increase the domain wall energy thus making nucleation more difficult while Al is thought to improve the wettability of the Nd-oxide phases.Bulk polished samples were examined in a JEOL 35CF scanning electron microscope (SEM) operated at 30keV equipped with a Be window energy dispersive spectrometer (EDS) detector in order to determine the phase distribution.


Author(s):  
W. Coene ◽  
F. Hakkens ◽  
T.H. Jacobs ◽  
K.H.J. Buschow

Intermetallic compounds of the type RE2Fe17Cx (RE= rare earth element) are promising candidates for permanent magnets. In case of Y2Fe17Cx, the Curie temperature increases from 325 K for x =0 to 550 K for x = 1.6 . X ray and electron diffraction reveal a carbon - induced structural transformation in Y2Fe17Cx from the hexagonal Th2Ni17 - type (x < 0.6 ) to the rhombohedral Th2Zn17 - type ( x ≥ 0.6). Planar crystal defects introduce local sheets of different magnetic anisotropy as compared with the ordered structure, and therefore may have an important impact on the coercivivity mechanism .High resolution electron microscopy ( HREM ) on a Philips CM30 / Super Twin has been used to characterize planar crystal defects in rhombohedral Y2Fe17Cx ( x ≥ 0.6 ). The basal plane stacking sequences are imaged in the [100] - orientation, showing an ABC or ACB sequence of Y - atoms and Fe2 - dumbbells, for both coaxial twin variants, respectively . Compounds resulting from a 3 - week annealing treatment at high temperature ( Ta = 1000 - 1100°C ) contain a high density of planar defects.


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