• Title/Summary/Keyword: Lorentz force density

Search Result 29, Processing Time 0.028 seconds

Study of micro-plastics separation from sea water with electro-magnetic force

  • Nomura, Naoki;Mishima, Fumihito;Nishijima, Shigehiro
    • Progress in Superconductivity and Cryogenics
    • /
    • v.23 no.3
    • /
    • pp.10-13
    • /
    • 2021
  • The method of removing micro-plastics from sea water has been developed using electro-magnetic force. Plastics are difficult to decompose and put a great load on the marine environment. Especially a plastic with a size of 5 mm or less is defined as micro-plastic and are carried by ocean currents over long distances, causing global pollution. These are not easily decomposed in the natural environment. The Lorentz force was generated in simulated sea water and its reaction force was applied to the micro-plastic to control their motion. Lorentz force was generated downward and the reaction force to the plastics was upward. The plastic used in the experiment was polystyrene with a diameter of 6 mm, and the density was 1.07 g/cm3. The polystyrene sphere levitated at the current density of 0.83 A/cm2 and the external field of 0.87T. The particle trajectory calculation was also made to design separation system using superconducting magnet.

Design and Analysis of Lorentz Force-type Magnetic Bearing Based on High Precision and Low Power Consumption

  • Xu, Guofeng;Cai, Yuanwen;Ren, Yuan;Xin, Chaojun;Fan, Yahong;Hu, Dengliang
    • Journal of Magnetics
    • /
    • v.22 no.2
    • /
    • pp.203-213
    • /
    • 2017
  • Magnetically suspended control & sensitive gyroscope (MSCSG) is a novel type of gyroscope with the integration of attitude control and attitude angular measurement. To improve the precision and reduce the power consumption of Lorentz Force-type Magnetic Bearing (LFMB), the air gap flux density distribution of LFMB has been studied. The uniformity of air gap flux density is defined to qualify the uniform degree of the air gap flux density distribution. Considering the consumption, the average value of flux density is defined as well. Some optimal designs and analyses of LFMB are carried out by finite element simulation. The strength of the permanent magnet is taken into consideration during the machining process. To verify the design and simulation, a high-precision instrument is employed to measure the 3-dimensional magnetic flux density of LFMB. After measurement and calculation, the uniform degree of magnetic flux density distribution reaches 0.978 and the average value of the flux density is 0.482T. Experimental results show that the optimal design is effective and some useful advice can be obtained for further research.

MHD (Magnetohydrodynamic) Micropump Using Lorentz Force (로렌츠 힘을 이용한 MHD(Magnetohydrodynamic) 마이크로펌프)

  • 장재성;이승섭
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.15 no.11
    • /
    • pp.93-99
    • /
    • 1998
  • We present a novel micropump of which pumping mechanism is based upon MHD (Magnetohydrodynamic) principle. The MHD micropump uses Lorentz force as pumping source. In the MHD micropump, Lorentz force is applied into initially stagnant conducting fluid to drive it in magnetic and electric field to flow in both directions. The performance of the MHD micropump is obtained by measuring the pressure head difference and flow rate as applied voltage changes from 10 to 60 V DC at 0.19 and 0.44 Tesla. The pressure head difference is 18 mm at 38 mA and the flow rate is 63 ${\mu}{\ell}$ /min at 1.8 mA when the inside diameter of inlet/outlet tube is 2 mm and the magnetic flux density is 0.44 Tesla.

  • PDF

Analysis of Lorentz force of radial magnetic field type vacuum interrupter using finite element method (유한요소해석을 통한 횡자계 방식의 진공인터럽터 전극의 로렌츠 힘 분석)

  • KIM, Byoung-Chul;YOON, Jae-Hun;HOE, Jun;KANG, Seong-Hwa;LIM, Kee-Joe
    • Proceedings of the KIEE Conference
    • /
    • 2008.07a
    • /
    • pp.1197-1198
    • /
    • 2008
  • There have been few papers using finite element method(FEM) to analyze arc driving force for spiral type vacuum interrupter electrode up to date while there have been many papers dealing with AMF type electrode by means of FEM. AMF analysis is very important in AMF type electrode because it has proportional relation with effective area which means the area of magnetic flux density above critical magnetic flux density to diffuse arc. In the same manner, arc driving force is an important factor to drive arc by Lorentz force. In this paper two models were calculated and compared by using commercial FEM software Maxwell 3D.

  • PDF

Magnetic Field Analysis of the Field Coil for 10 MW Class Superconducting Wind Turbines (10 MW급 초전도 풍력발전기 계자코일 전자장 해석)

  • Kim, Ji-Hyung;Park, Sa-Il;Kim, Ho-Min
    • Progress in Superconductivity and Cryogenics
    • /
    • v.14 no.3
    • /
    • pp.18-22
    • /
    • 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.

Effect of Process Parameters in Electromagnetic Forming Apparatus on Forming Load by FEM (유한요소해석을 통한 전자기 성형장비 공정변수의 성형력에 미치는 영향)

  • Noh, Hak Gon;Park, Hyeong Gyu;Song, Woo Jin;Kang, Beom Soo;Kim, Jeong
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.30 no.7
    • /
    • pp.733-740
    • /
    • 2013
  • The high-velocity electromagnetic forming (EMF) process is based on the Lorentz force and the energy of the magnetic field. The advantages of EMF include improved formability, wrinkle reduction, and non-contact forming. In this study, numerical simulations were conducted to determine the practical parameters for the EMF process. A 2-D axis-symmetric electromagnetic model was used, based on a spiral-type forming coil. In the numerical simulation, an RLC circuit was coupled to the spiral coil to measure various design parameters, such as the system input current and the electromagnetic force. The simulation results show that even though the input peak current levels were at the same level in each case, the forming condition varied due to differences in the frequency of the input current. Thus, the electromagnetic forming force was affected by the input current frequency, which in turn, determined the magnitude of the current density and the magnetic flux density.

Lorentz Force Density Distribution of a Current Carrying Superconducting Tape in a Perpendicular Magnetic Field

  • Yoo, J.;Kwak, K.;Rhee, J.;Park, C.;Youm, D.;Park, B.J.;Han, Y.H.
    • Progress in Superconductivity and Cryogenics
    • /
    • v.12 no.4
    • /
    • pp.13-16
    • /
    • 2010
  • The Lorentz force distribution of a high $T_c$ superconducting tape with increasing transport currents in magnetic field ($H_a$) was visualized. The external magnetic field was applied normally to the coated conductor tape surface after zero-field cooling, and the transport current ($I_a$) was increased stepwise from 0 to 90 % of the values of the critical current ($I_c$ ($H_a$)) at applied filed, Ha. The field distribution (H(x)) near the sample surface across the tape width (2w) was measured using the scanning Hall probe method. Applying an inversion to the measured field distribution, we obtained the underlying current distribution (J(x)), from which the magnetic induction, B(x) was calculated with Biot-Savart law. Then Lorentz force per unit length was calculated using F(x)=J(x)${\times}$B(x), which appears to be very inhomogeneous along the tape width due to the complicated distributions of J(x) and B(x).

Design of a Free Bulge Test Coil Using Electromagnetic Forces and Comparison between Experimental and Numerical Results (전자기력 자유벌지 실험을 위한 성형코일 설계 및 3-D 해석비교)

  • Kim, H.K.;Noh, H.G.;Kang, B.S.;Kim, J.
    • Transactions of Materials Processing
    • /
    • v.23 no.7
    • /
    • pp.431-438
    • /
    • 2014
  • For electromagnetic forming(EMF) the most important feature is a forming coil which creates the electromagnetic force(Lorentz force), using current density and a magnetic field. Most previous papers have concentrated on the final configuration of the blank or the efficiency of EMF process. Studies focused on the design parameters affected by the forming coil performance have not been conducted. In order to design a suitable forming coil for an object, the current study uses LS-DYNA EM-Module to not only optimize the coil but also to examine the effect of coil performance. By this method a suitable forming coil was made and tested to determine whether or not good formability was achieved in a free bulge test Numerical analysis was also used. The workpiece was Al 1100-O with a thickness of 1.27mm and the coil was made from copper CW004A, which has good electrical conductivity and is suitable for electrical components.

Critical Characteristics Estimation of a Large-Scale HTS Wind Turbine Generator Using a Performance Evaluation System

  • Kim, Taewon;Woo, Sang-Kyun;Kim, Changhyun
    • KEPCO Journal on Electric Power and Energy
    • /
    • v.5 no.3
    • /
    • pp.229-233
    • /
    • 2019
  • Large-scale High Temperature Superconducting (HTS) wind power generators suffer from high electromagnetic force and high torque due to their high current density and low rotational speed. Therefore, the torque and Lorentz force of HTS wind power generators should be carefully investigated. In this paper, we proposed a Performance Evaluation System (PES) to physically test the structural stability of HTS coils with high torque before fabricating the generator. The PES is composed of the part of a pole-pair of the HTS generator for estimating the characteristic of the HTS coil. The 10 MW HTS generator and PES were analyzed using a 3D finite element method software. The performance of the HTS coil was evaluated by comparing the magnetic field distributions, the output power, and torque values of the 10 MW HTS generator and the PES. The magnetic flux densities, output power, and torque values of the HTS coils in the PES were the same as a pole-pair of the 10 MW HTS generator. Therefore, the PES-based evaluation method proposed in this paper can be used to estimate the critical characteristics of the HTS generator under high magnetic field and high torque before manufacturing the HTS wind turbines. These results will be used effectively to research and manufacture large-scale HTS wind turbine generators.

Numerical analysis of the electromagnetic force for design optimization of a rectangular direct current electromagnetic pump

  • Lee, Geun Hyeong;Kim, Hee Reyoung
    • Nuclear Engineering and Technology
    • /
    • v.50 no.6
    • /
    • pp.869-876
    • /
    • 2018
  • The force of a direct current (DC) electromagnetic pump used to transport liquid lithium was analyzed to optimize its geometrical and electrical parameters by numerical simulation. In a heavy-ion accelerator, which is being developed in Korea, a liquid lithium film is utilized for its high charge-stripping efficiency for heavy ions of uranium. A DC electromagnetic pump with a flow rate of $6cm^3/s$ and a developed pressure of 1.5 MPa at a temperature of $200^{\circ}C$ was required to circulate the liquid lithium to form liquid lithium films. The current and magnetic flux densities in the flow gap, where a $Sm_2Co_{17}$ permanent magnet was used to generate a magnetic field, were analyzed for the electromagnetic force distribution generated in the pump. The pressure developed by the Lorentz force on the electromagnetic force was calculated by considering the electromotive force and hydraulic pressure drop in the narrow flow channel. The opposite force at the end part due to the magnetic flux density in the opposite direction depended on the pump geometrical parameters such as the pump duct length and width that defines the rectangular channels in the nonhomogeneous distributions of the current and magnetic fields.