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MULTI-FIELD COUPLING BEHAVIOR OF SIMPLY-SUPPORTED CONDUCTIVE PLATE UNDER THE CONDITION OF A TRANSVERSE STRONG IMPULSIVE MAGNETIC FIELD

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Acta Mechanica Solida Sinica 2006年第3期19卷 203-211页

作者： Zhu Linli Zhang Jianping Zheng Xiaojing Department of Mechanics and Engineering Science Lanzhou University Lanzhou 730000 China

In order to study the multi-field coupling mechanical behavior of the simply-supported conductive rectangular thin plate under the condition of an externally lateral strong impulsive magnetic field, that is the dynamic buckling phenomenon of the thin plates in the effect of the magnetic volume forces produced by the interaction between the eddy current and the magnetic fields, a FEM analysis program is developed to characterize the phenomena of magnetoelastic buckling and instability of the plates. The critical values of magnetic field for the three different initial vibrating modes are obtained, with a detailed discussion made on the effects of the lengththickness ratio a/h of the plate and the length-width ratio a/b as well as the impulse parameter on the critical value BOcr of the applied magnetic field.

关键词： multi-field coupling conductive thin plate impulsive magnetic field eddy current dynamic buckling magnetic volume forces

Design and analysis of an underwater inductive coupling power transfer system for autonomous underwater vehicle docking applications

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第1期15卷 51-62页

作者： Jian-guang SHI De-jun LI Can-jun YANG State Key Laboratory of Fluid Power Transmission and Control

We develop a new kind of underwater inductive coupling power transfer(ICPT)system to evaluate wireless power transfer in autonomous underwater vehicle(AUV)docking *** that determine the performance of the system are systematically analyzed through mathematical methods.A circuit simulation model and a finite element analysis(FEA)simulation model are developed to study the power losses of the system,including copper loss in coils,semiconductor loss in circuits,and eddy current loss in transmission *** characteristics of the power losses can provide guidelines to improve the efficiency of ICPT *** results and simulation results are validated by relevant experiments of the prototype *** output power of the prototype system is up to 45 W and the efficiency is up to *** preliminary results indicate that the efficiency will increase as the transmission power is raised by increasing the input *** the output power reaches 500 W,the efficiency is expected to exceed *** efficiency can be further improved by choosing proper semiconductors and *** analysis methods prove effective in predicting the performance of similar ICPT systems and should be useful in designing new systems.

关键词： Inductive coupling power transfer(ICPT) Autonomous underwater vehicle(AUV) docking Coupling coefficient Resonant capacitance Power transfer efficiency Power loss eddy current

Improved Electrical Insulation of Rare Earth Permanent Magnetic Materials With High Magnetic Properties

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Journal of Iron and Steel Research International 2009年第2期16卷 84-88页

作者： CHANG Ying WANG Da-peng LI Wei PAN Wei YU Xiao-jun QI Min School of Automotive Engineering Dalian University of Technology Dalian 116024 Liaoning China School of Material Science and Technology Dalian University of Technology Dalian 116024 Liaoning China Functional Materials Research Institute China Iron and Steel Research Institute Group Beijing 100081 China

Rare earth permanent magnetic materials are typical electrical conductor, and their magnetic properties will decrease because of the eddy current effect, so it is difficult to keep them stable for a long enough time under a high frequency AC field. In the present study, as far as rare earth permanent magnets are concerned, for the first time, rare earth permanent magnets with strong electrical insulation and high magnetic performance have been obtained through experiments, and their properties are as follows：（i） Sm1 TM17 ： Br=0. 62 T, jHc=803.7 kA/m, （BH）m= 58.97 kJ/m^3, p=7 Ω· m; （2） NdFeB： Br=0.485 T, jHc=766.33 kA/m, （BH）m=37.96 kJ/m^3, ρ=Ω · m. The magnetic properties of Sm2TM17 and NdFeB are obviously higher than those of ferrite permanent magnet, and the electric insulating characteristics of Sm2TM17 and NdFeB applied have in fact been approximately the same as those of ferrite. Therefore, Sm2TM17 and NdFeB will possess the ability to take the place of ferrite under a certain high frequency AC electric field.

关键词： Sm2 TM17 NdFeB electrical insulation eddy current

Performance characterization on downwash flow and spray drift of multirotor unmanned agricultural aircraft system based on CFD

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International Journal of Agricultural and Biological Engineering 2022年第3期15卷 1-8页

作者： Hongze Li Hang Zhu Zihao Jiang Yubin Lan School of Mechanical and Aerospace Engineering Jilin UniversityChangchun 130022China School of Agricultural Engineering and Food Science Shandong University of TechnologyZibo 255000ShandongChina Department of Biological and Agricultural Engineering Texas A&M UniversityTexas77843USA

In recent years,multi-rotor Unmanned Aerial Vehicles(UAVs)have been employed in the field of plant protection in *** drift has been considered a major impact in agriculture aerial spraying,and spray quality in the application of plant protection *** downwash including wake vortices and downward wind field plays a major role in the dispersal and deposition of pesticide spray released by nozzle(s)equipped in *** from the fixed-wing UAV,the downwash flow of multi-rotor UAV was result from the rotation of ***,a study on off-target drift and ground deposit concerning the rotor rotation was simulated through a series of Computational Fluid Dynamics(CFD)simulations to obtain the influence of *** discrete Phase Model(DPM)was taken to simulate the motion of droplet particles since it is an appropriate way to simulate discrete phases in flow field and can track particle *** this study,the parameters of CFD simulations were acquired by three kinds of actual replicated *** simulation analysis mainly obtains the droplet drift and deposition rule,the influence of eddy current,and downwash flow caused by the rotor *** results showed that the downwash distribution below different rotors was different owing to the flight angle of inclination,“behind”is the greatest,“middle”is secondly,and“forward”is smallest in value(behind,middle,and forward represent three regions below rotors along flight direction).According to the simulation results,two methods of reducing droplet drift were put forward and specific simulations were carried out to prove their *** results of this study can provide theoretical support for improving the spray quality of UAV and reducing the drift of droplets.

关键词： Unmanned Aerial Vehicles spray drift downward wind field rotor rotation eddy current downwash distribution

Control of the Vertical Instability in the SUNIST Spherical Tokamak

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Plasma Science and Technology 2009年第3期11卷 265-268页

作者：曾龙高喆何也熙 Sino-United Spherical Tokamak Laboratory Department of Engineering PhysicsTsinghua University

Control of the vertical instability of the plasma in the SUNIST spherical tokamak is studied. A proportional-derivative （PD） position controller is employed in a control system which consists of a massless plasma, active coils and a passive conducting vessel. Stability conditions axe determined and the feedback control with different combinations of both active and passive coils, available on SUNIST, is emphasized. The simulation results are also discussed.

关键词： SUNIST vertical instability active coils eddy current

Development of the pulse bump magnet in HEPS

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Radiation Detection Technology and Methods 2023年第4期7卷 521-530页

作者： Lihua Huo Jinhui Chen Guanwen Wang Lei Wang Yuemei Peng Zhe Duan Yuanyuan Guo Guanjian Wu Xinzhe Zhai Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China University of Chinese Academy of Sciences CASBeijing100049China

Purpose In the extraction process from booster to storage ring(BTS)for high energy photon source(HEPS),the implementation of four pulse bump magnets plays a crucial role in creating a localized *** serves to effectively reduce the upstream kicker strength and facilitate the extraction *** this paper,the development of four pulse bump magnets is presented,which were meticulously designed and thoroughly discussed,taking into consideration dynamic characteristics of the pulse magnet such as magnetic field,eddy current,induced voltage,and *** The magnetic field and eddy currents of the pulse bump magnet were calculated through simulation using OPERA/ELLEKTRA,based on the 3D *** design of the magnet incorporated the utilization of eddy currents within the vacuum chamber to achieve improved field ***,the measurements were performed to validate the magnet's *** The central magnetic field,integral magnetic field,effective length,and field uniformity measured for the first magnet meet the design *** temperature measurement of the first magnet indicates that the temperature in the magnet was within acceptable *** measurement results for the other three magnets are consistent with those of the first *** The magnetic field performances of four pulse bump magnets meet the physical requirements for beam extraction in BTS of ***,the magnets have demonstrated reliable operation during extended testing periods.

关键词： Pulse bump magnet Magnetic field eddy current Induced voltage Vibration Measurement

Experimental Study and Numerical Visualization of Physical Fields of Electromagnetic Pumps Constructed on Permanent Magnets

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Journal of Iron and Steel Research International 2012年第S2期19卷 621-624页

作者： KOLESNIKOV Yurii WANG Xiaodong THESS André Institute Thermo and Fluid Mechanics Ilmenau University of Technology Graduate University of Chinese Academy of Sciences College of Materials Science and Opto-Electronic Technology

Pumps with magnet systems constructed on permanent magnets and performed in two manners like two-disk type and the cylindrical rotor type are ***,by way of example we consider the experimental study of disk pump with straight channel;second,we analyse the results of numerical simulation of cylindrical pump in two cases,namely,of straight and U-bend forms of pump *** a high speed of pump rotation when induced magnetic field becomes essential in as against the applied field,*** the skin-effect takes place,the pump characteristics are *** of physical fields of the pumps is reported.

关键词： electromagnetic pump magnetic field distribution Lorentz force eddy current pressure flow rate

Research on high-Tc SQUID based non-destructive evaluation

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Chinese Physics B 2004年第1期13卷 19-23页

作者：王会武孔祥燕任育峰于洪伟丁红胜赵士平陈赓华周岳亮张利华何豫生杨乾声 InstituteofPhysics ChineseAcademyofSciencesBeijing100080China

A non-destructive evaluation system based on high-Tc dc-SQUID (superconducting quantum interference device) incorporating a gradient field excitation has been built. By using this system a 1mm-diameter hole at a depth of 2mm inside an aluminium plate at room temperature can be easily detected and imaged in an unshielded environment. The relation between the spatial resolution, or the smallest detectable flaw size and experimental parameters is briefly analysed in terms of a simple metal ring model. The result shows that the spatial resolution depends strongly on the sensor-sample separation as well as on some other parameters, such as signal-to-noise ratio of excitation, excitation frequency and material conductivity.

关键词： SQUID resolution eddy current

Optimal Design of Electromagnetic Acoustic Transducer

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Journal of Energy and Power Engineering 2012年第4期6卷 561-569页

作者： Eiji Matsumoto Shinji Kitamura Jun Abe Department of Energy Conversion Science Kyoto University Kyoto 606-8501 Japan Kyoto Research ＆ Development Center Mitsubishi Motors Corporation Kyoto 616-8501 Japan Energy Technology Laboratories Osaka Gas Osaka 554-0051 Japan

This paper considers the design of EMAT （Electro-Magnetic Acoustic Transducer） based on numerical simulation. The EMAT consists of an exiting coil and two permanent magnets, which transmits the ultrasonic wave by the Lorentz force between the eddy current and the static magnetic field by the magnets. From the experimental result on self-prepared EMATs, the intensity and the directivity of the transmitted wave depend on the widths of the coil and the magnets. By means of EEM analysis the authors attempt to determine the optimal values of the above widths such that both the intensity and the directivity achieve the maximum or allowable performance.

关键词： Acoustics actuators eddy current electromagnetic acoustic transducer finite element methods magnetic forces sensors