• Journal of Mechanical Science and Technology
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• 제15권12호
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• pp.1876-1881
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• 2001

We present the numerical analysis of the growth of a silicon (Si) single crystal. In the MCZ (Magnetic-field-applied Czochralski) method, two magnetic fields that stand opposite to each other generate a cusp magnetic field. In this work, the three cusp magnetic fields used for the analysis are an extern magnetic field, a surface magnetic field and an internal magnetic field. Each case was evaluated mainly as to the degree of stirring, shaft symmetry and the stability of the flow. As a result, the cusp magnetic field that yielded to best conditions was the internal magneic field.

• 한국재료학회지
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• 제11권12호
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• pp.1091-1095
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• 2001

Finite element analysis showed that strong magnetic fields were distributed around the arc furnace where the strongest magnetic field was generated around the three phase cables, and followed by the electrodes and the mast arm in decreasing order. Magnetic field decay patterns around the arc furnace could be fitted by introducing exponential formula,$Y=Y_0+Ae^{\frac-{x}{t}}$. These results showed that magnetic field intensities around the arc furnace could be estimated at any 3-dimensional positions using the finite element method (FEM).

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권10호
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• pp.501-506
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• 2003

A Superconducting Rotary Machine (SRM) is characterized by an air-cored machine with its rotor iron and stator iron teeth removed. For this reason, the SRM is featured by 3D magnetic flux distribution, which decreases in the direction of axis. Therefore, 3D magnetic field analysis method is required to know about characteristic of magnetic field distribution of SRM. In this paper, 3D flux distribution of SRM is calculated by analytical method. The magnetic field distribution of the field coils is calculated by Biot-Savart equation. The magnetic core is represented by magnetic surface polarities. This paper describes the combined use of above methods for the total field computation, and compares results of analytical method and 3D FEM(Finite Element Method).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.169-171
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• 1996

Recently, the finite element analysis(FEM) using two dimensional magnetic permeability tensor was introduced to calculate the magnetic field considering the rotational hysteresis. We obtain the tensor matrix from the measured data using two-dimensional magnetic measuring apparatus. We calculate the induced magnetic flux density and the rotational hysteresis loss under the model with the same condition with the measuring apparatus. Therefore we show that FEM with tensor can be used to calculate the magnetic flux density and the rotational hysteresis loss in the arbitrary rotational magnetic field.

• 한국초전도ㆍ저온공학회논문지
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• 제14권3호
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• pp.18-22
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• 2012

This paper presents the magnetic field analysis of the racetrack double pancake field coil for the 10 MW class superconducting wind turbine which is considered to be the next generation of wind turbines using the 3 Dimensional FEM(Finite Elements Method). Generally, the racetrack-shaped field coil which is wound by the second generation(2G) superconducting wire in the longer axial direction is used, because the racetrack-shaped field coil generates the higher magnetic field density at the minimum size and reduces the synchronous reactance. To analysis the performance of the wind turbines, It is important to calculate the distribution of magnetic flux density at the straight parts and both end sections of the racetrack-shaped high temperature superconductivity(HTS) field coil. In addition, Lorentz force acting on the superconducting wire is calculated by the analysis of the magnetic field and it is important that through this way Lorentz force can be used as a parameter in the mechanical analysis which analyzes the mechanical stress on the racetrack-shaped field coil.

• Journal of Magnetics
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• 제8권2호
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• pp.79-84
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• 2003

Finite element analysis showed that strong magnetic fields were distributed around the arc furnace where the strongest magnetic fields were generated around the three phase cables. The second and third strongest fields near the arc furnace were found to be generated around the electrodes and the mast-arms, respectively. The generated field intensities were greatly influenced by the mast arm structure of the arc furnace as well as the phase differences and operation currents of the supplied power, Magnetic field decay patterns around the arc furnace could be smoothly fitted by this equation of exponential formula, H=H$0_$+Ae$^{\frac{r}{t}}$. These results revealed that magnetic field intensities around the arc furnace could be estimated at any 3-dimensional position using finite element method (FEM).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.609-612
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• 2001

To investigate the magnetic field distribution of power line, we used amorphous wire sensor. And we discuss extremely low frequency magnetic field distribution dependent upon arrangement of power line and shielding pipe made from iron or alumimum materials by both measurement and FEM(Finite Element Method) analysis. Appling current of single phase 60 [Hz] 15 [A] is supplied to copper wire coated enamel resign. As the results, we confirmed that linear characteristics of amorphous wire sensor is very excellent and measurement value agrees with FEM calculation. Magnetic field distribution due to shielding materials is changed by permeability and conductivity.

• 한국초전도ㆍ저온공학회논문지
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• 제15권1호
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• pp.29-34
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• 2013

AMR (Active Magnetic Regenerative) refrigerators require the large variation of the magnetic field and a HTS magnet can be used. The amount of AC loss is very important considering the overall efficiency of the AMR refrigerator. However, it is very hard to estimate the precise loss of the HTS magnet because the magnetic field distribution around the conductor itself depends on the coil configuration and the neighboring HTS wires interact each other through the distorted magnetic field by the screening current Therefore, the AC loss of HTS magnet should be calculated using the whole configuration of the HTS magnet with superconducting characteristic. This paper describes the AC loss of the HTS magnet by an appropriate FEM approach, which uses the non-linear characteristic of HTS conductor. The analysis model is based on the 2-D FEM model, called as 'magnetic field formulation and edge-element model', for whole coil configuration in cylindrical coordinates. The effects of transport current and stacked conductors on the AC loss are investigated considering the field-dependent critical current. The PDE model of 'Comsol multiphysics' is used for the FEM analysis with properly implemented equations for axisymmetric model.

• 한국전기전자재료학회논문지
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• 제16권10호
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• pp.952-957
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• 2003

The purpose of this paper is analyses about in 12kV/50kA vacuum interrupter with an axial magnetic field type electrode system through the studies of electromagnetic phenomena. Vacuum interrupter is important in electric safety part. In this paper, we performed analysis of electric field, magnetic field, current density in AMF electrode using the Maxwell 3D simulation. The current distribution and magnetic field in simple models are analyzed to verify its efficiency and accuracy. In addition the validity of FEM is confirmed by performing the analyses of distribution in current density and magnetic flux density.

• 한국군사과학기술학회지
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• 제10권4호
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• pp.38-51
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• 2007

This paper describes research results for the measurement and analysis method of magnetic signatures generated from the ship's magnetic mock-up model. In this paper, we present the theoretical and experimental techniques for the separation of the permanent and the induced magnetic field from the measured magnetic signature of the mock-up model. Also, we describe the prediction method of the induced magnetic field generated from mock-up model using the Magnet s/w, one of the FEM analysis tools for the electro-magnetic field and the magnetic dipole modelling method based on the least square techniques. The proposed modelling and analysis methods can be used for the prediction and the analysis of the static magnetic field generated from the real naval ship as well as the mock-up model.