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Acta Mechanica Solida Sinica 2019年第3期32卷 298-309页

作者： Ye-Wei Zhang Zhi-Wei Fang Shi-Lei Wang Zhi-Yu Ni Jian Zang Bo Fang College of Aerospace Engineering Shenyang Aerospace University Shenyang 110136 China Shanghai Prime Machinery Company Limited Shanghai 200072 China

This paper presents a new device integrating a nonlinear vibration absorber with a levitation magnetoelectric energy harvester for whole-spacecraft systems. This device effectively reduces vibration and has a stronger energy harvesting capability than the existing systems. It harvests energy from a wide frequency range and has a high output voltage. The harvested energy is determined by magnetic field strength, excitation frequency, and resistive load. The change in the magnetic field strength has the least impact on the output voltage. The vibration reduction effects and harvested energy of the system are analyzed with an approximate analytical method that combines the harmonic balance approach and the pseudo-arclength continuation algorithm. The results of the Runge-Kutta method are nearly consistent with those of the approximate analytical method. Moreover, the effects of the excitation frequency, resistive load, and parameters of the nonlinear energy sink on the system vibration response and energy harvesting are analyzed.

关键词： levitation magnetoelectric energy harvester Whole spacecraft Nonlinear energy sink Vibration reduction

Physical Properties of Liquid Terbium Measured by levitation Techniques

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Journal of Rare Earths 2007年第6期25卷 665-669页

作者： Paul-Francois Paradis Takehiko Ishikawa Noriyuki Koike Yuki Watanabe Japan Aerospace Exploration Agency Institute of Space and Astronautical Science ISS Science Project Office 2-1-1 Sengen Tsukuba Ibaraki 305-8505 Japan Chiba Institute of Technology Tsudanuma Narashino Chiba Japan Advanced Engineering Service Co. Ltd. Tsukuba Ibaraki 305-0032 Japan

To understand the nature and behavior of rare earth metals in their liquid phases, accurate values of their physical properties are essential. However, to measure their physical properties, the samples should be maintained in liquid phases for prolonged time, and this raises a formidable challenge. This is mainly explained by their high melting temperatures （e.g., 1629 K for Tb）, high vapor pressure, and the risk of melt contamination with a crucible or support. An electrostatic levitation furnace alleviated these difficulties and allowed the determination of density, surface tension, and viscosity of several metals above their melting temperature. Here, first, the levitation furnace facility and the noncontact diagnostic procedures were briefly discussed, followed by the explanation of their thermophysical property measurements over wide temperature ranges. The density was obtained using an ultraviolet-based imaging technique that allowed excellent illumination, even at elevated temperatures. Over the 1615 to 1880 K temperature span, the density measurements could be expressed as p（T） =7.84 × 10^3 -0.47 （T - Tm）（kg · m^-3） with Tm = 1629 K, yielding a volume expansion coefficient a（T） = 6.0 × 10^-5 （K^-1）. In addition, the surface tension and the viscosity could be determined by inducing a drop oscillation to a molten sample. Using this technique, the surface tension data could be expressed as σ（T） = 8.93 × 10^2 - 0.10 （T - Tm）（mN· m^-1） and those for viscosity as η（T） =0.583 exp [4.1 × 10^4/（RT）] （MPa·s） over the 1690 to 1980 K temperature range

关键词： levitation liquid noncontact terbium rare earths

ELECTROMAGNETIC MODEL OF levitation MELTING WITH COLD CRUCIBLE

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中国有色金属学会会刊：英文版 1996年第2期6卷 12-17页

作者： Deng Kang Zhou Yueming Ren Zhongming Zhu Shoujun Wei Jihe Jiang Guochang(Shanghai Enhanced Laboratory of Ferrometallurgy,Shanghai University, Shanghai 200072) Shanghai Enhanced Laboratory of Ferrometallurgy Shanghai University Shanghai 200072 China

ＥＬＥＣＴＲＯＭＡＧＮＥＴＩＣＭＯＤＥＬＯＦＬＥＶＩＴＡＴＩＯＮＭＥＬＴＩＮＧＷＩＴＨＣＯＬＤＣＲＵＣＩＢＬＥＤｅｎｇＫａｎｇ；ＺｈｏｕＹｕｅｍｉｎｇ；ＲｅｎＺｈｏｎｇｍｉｎｇ；ＺｈｕＳｈｏｕｊｕｎ；ＷｅｉＪｉｈｅ；... 详细信息

ＥＬＥＣＴＲＯＭＡＧＮＥＴＩＣＭＯＤＥＬＯＦＬＥＶＩＴＡＴＩＯＮＭＥＬＴＩＮＧＷＩＴＨＣＯＬＤＣＲＵＣＩＢＬＥＤｅｎｇＫａｎｇ；ＺｈｏｕＹｕｅｍｉｎｇ；ＲｅｎＺｈｏｎｇｍｉｎｇ；ＺｈｕＳｈｏｕｊｕｎ；ＷｅｉＪｉｈｅ；ＪｉａｎｇＧｕｏｃｈａｎｇ（Ｓｈａ...

关键词： cold crucible electromagnetic induction levitation melting

Ambiguous temperature difference in aerodynamic levitation process: Modelling, solving and application

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Journal of Materials Science & Technology 2019年第8期35卷 1636-1643页

作者： Xuan Ge Xiaowei Xu Qiaodan Hu Wenquan Lu Liang Yang Sheng Cao Mingxu Xia Jianguo Li School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China Shanghai Key Laboratory of Materials Laser Processing and Modification Shanghai Jiao Tong University Shanghai 200240 China Monash Centre for Additive Manufacturing (MCAM) Monash University Clayton VIC 3800 Australia

The aerodynamic levitation provides an efficient technique for the research on thermophysical properties and solidification behavior of refractory materials. However, there is a nonnegligible temperature differences across sample, causing unexpected uncertainty of measurement, such as, thermal expansivity and undercooling limit. We establish thermal filed model with properly simplified boundary condition, and derive quantitative expressions of this ambiguous temperature difference. Here we show that the temperature difference not only related to the average temperature, relative size and thermal conductivity of sample, but significantly influenced by the rotation pattern of sample. A huge temperature differences is almost inevitable when the sample with low thermal conductivity and high melting point is smelted in stationary suspension pattern, however, a drastically reduction of temperature difference can be fulfilled by simply making the sample rotation in up to down pattern. The thermal filed simulation was used to confirm the validity of these theoretical expressions. This work shed light on temperature difference in aerodynamic levitation. Based on this work, one can simply estimate the extent of temperature difference across the sample, and regulated that conveniently if needed, which benefit for novel material preparation and solidification mechanism study based on this technique.

关键词： Solidification levitation Modelling Temperature difference

NUMERICAL　SIMULATION　OF　ALTERNATIVE　HORIZONTAL　levitation　ELECTROMAGNETIC　CONTINUOUS　CASTING（Ⅱ）

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中国有色金属学会会刊：英文版 1996年第4期6卷 42-46页

作者： Zhu Shoujun Ren Zhongming Deng Kang Jiang Guochang(Shanghai Enhanced Laboratory of Ferrometallurgy,Shanghai University,Shanghai 200072) Shanghai Enhanced Laboratory of Ferrometallurgy Shanghai University Shanghai 200072 China

ＮＵＭＥＲＩＣＡＬＳＩＭＵＬＡＴＩＯＮＯＦＡＬＴＥＲＮＡＴＩＶＥＨＯＲＩＺＯＮＴＡＬＬＥＶＩＴＡＴＩＯＮＥＬＥＣＴＲＯＭＡＧＮＥＴＩＣＣＯＮＴＩＮＵＯＵＳＣＡＳＴＩＮＧ（Ⅱ）￥ＺｈｕＳｈｏｕｊｕｎ；ＲｅｎＺｈｏｎｇｍ... 详细信息

ＮＵＭＥＲＩＣＡＬＳＩＭＵＬＡＴＩＯＮＯＦＡＬＴＥＲＮＡＴＩＶＥＨＯＲＩＺＯＮＴＡＬＬＥＶＩＴＡＴＩＯＮＥＬＥＣＴＲＯＭＡＧＮＥＴＩＣＣＯＮＴＩＮＵＯＵＳＣＡＳＴＩＮＧ（Ⅱ）￥ＺｈｕＳｈｏｕｊｕｎ；ＲｅｎＺｈｏｎｇｍｉｎｇ；ＤｅｎｇＫａｎｇ；Ｊｉａｎ...

关键词： horizontal electromagnetic continuous casting electromagnetic levitation numerical simulation

Effect of induced shielding current transmission in longitudinal direction on levitation force of melt grown single-domain YBa_2Cu_3O_(7-x) cylindrical superconductor

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Science China(Physics,Mechanics & Astronomy) 2004年第2期47卷 146-153页

作者： R. Nicolsky R. de Andrade Jr LASUP-DEE UFRJ Ilha do Fundao Cx.P.68515 21945-970 Rio de Janeiro RJ Brasil Correspondence should be addressed to Yang Wanmin LASUP-DEE UFRJ Ilha do Fundao Cx.P.68515 21945-970 Rio de Janeiro RJ Brasil Correspondence should be addressed to Yang Wanmin

A novel layer deletion method is used to experimentally investigate the effect of induced shielding current transmission (ISCT) in the longitudinal direction on the levitation force of a single-domain YBa2Cu3O7-x (YBCO) cylindrical superconductor (f30? mm). In the experiment the sample was gradually sliced into two equal sheets, at the middle height along a diameter with 5 mm every step. The experimental results show that the levitation force is closely related with the ISCT in the longitudinal direction. Any layer deletion, even a small piece of layer deletion can reduce the levitation force of the sample. After the whole layer was deleted the levitation force can diminish about 50%. It is also found that the levitation force is directly proportional to the effective factor of surface area, which is equal to the top surface area divided by the total surface area parallel to the top surface of the sample.

关键词： melt growth, single domain YBCO, levitation force, induced current distribution.

Single-axis ultrasound levitation system with annular clamping forces

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Chinese Journal of Acoustics 2019年第2期38卷 189-200页

作者： YIN Guanjun LI Pan FAN Haoran GUO Jianzhong Institute of Applied Acoustics School of Physics and Information TechnologyShaanxi Normal University

Based on the principle of acoustic levitation,a single-axis ultrasonic levitation system(SAULS) with convex sides was designed.A normal SAULS only provides a levitation force(LF) against the gravity of the sample.While,such systems also provide an annular clamping force(ACF) surrounding the levitated samples,and improve levitation stability of samples in the standing wave field.Using the finite-difference time-domain method,we investigated the force distributions in different resonance cavities and the factors that influence the magnitude of the levitation force in optimizing the SAULS and the ACF.The theoretical analyses and experimental results indicate that the stability of levitation in this special SAULS is improved with the ACF from its designed convex-side feature.It can be developed into a simple device in levitating and moving samples steadily in related experiments and applications.

关键词： ACF Single-axis ultrasound levitation system with annular clamping forces

Maximization of Acoustic Levitating Force for a Single-Axis Acoustic levitation System Using the Finite Element Method

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Chinese Physics Letters 2019年第3期36卷 49-52页

作者： Saurabh Yadav Arpan Gupta Acoustic and Vibration Laboratory School of Engineering Indian Institute of Technology Mandi

We investigate single-axis acoustic levitation using standing waves to levitate particles freely in a medium bounded by a driver and a reflector. The acoustic pressure at the pressure antinode of the standing wave counteracts the downward gravitational force of the levitating object. The optimal relationship between the air gap and the driving frequency leads to resonance and hence maximization of the levitating force. Slight deviation from the exact resonance condition causes a reduction in acoustic pressure at the pressure antinodes. This results in a significant reduction of the levitating force. The driving frequency is kept constant while the air gap is varied for different conditions. The optimal air gap for maximizing the levitation force is studied for first three resonance modes. Furthermore, a levitating particle is introduced between the driver and the reflector. The dependence of the resonance condition on the size of the levitating particle as well as the position of the particle between the driver and the reflector has also been studied. As the size of the levitating particle increases, the resonance condition also gets modified. Finite element results show a good agreement with the validated results available in the literature. Furthermore, the finite element approach is also used to study the variation of acoustic pressure at the pressure antinode with respect to the size of the reflector. The optimum diameter of the reflector is calculated for maximizing the levitating force for three resonance modes.

关键词： Maximization Levitating Acoustic levitation Method

Computation and Analysis of Propellant and levitation Forces of a Maglev System Using FEM Coupled to External Circuit Model

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Journal of Electromagnetic Analysis and Applications 2010年第4期2卷 270-275页

作者： Shiyou Yang Lin Yang Qiang Zhou 不详

This paper studies the propellant and levitation forces of a prototype maglev system where the propellant forces are provided by a linear motor system. For this purpose, the mathematical model and method using finite element method coupled to external circuit model is developed. The details of the propellant and levitation forces for a prototype maglev system under different operating conditions are investigated, and some directions are given for practical engineering applications.

关键词： Maglev System Propellant Force levitation Force Numerical Computation Finite Element Method

Design and Development of Impeller Synergic Systems of Electromagnetic Type to levitation/Suspension Flight of Symmetrical Bodies

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Journal of Electromagnetic Analysis and Applications 2012年第1期4卷 42-52页

作者： Francisco Bulnes Juan Carlos Maya Isaías Martínez 不详

Using certain models of twistor surfaces for fields of force and the mathematical relationships that lie among fields, lines, surfaces and flows of energy, it has been designed and developed a flight electromagnetic type system based on the synergic study of their electromagnetic field geodesics to generate vehicle levitation, suspension and movement without being in contact with the surface. The idea of such work is to obtain a new flight and impulse patent of an electromagnetic vehicle by principles of super-conduction and some laws of the current like Eddy currents and principles which are very similar to mechanics of sidereal objects like galaxies or stars under models of twistor surfaces. This vehicle will be controlled by one microchip that will be programmed by conscience operators algebra of electromagnetic type that leads to the flow of Eddy currents, the iso-rotations and suspension of the special geometrical characteristics vehicle, generating also on the vehicle structure certain “magnetic conscience” that provokes all movements like succeeding to the sidereal objects in the universe.

关键词： Electromagnetic levitation Twistor Surfaces of Impulse Symmetrical Space of Iso-Rotations Superconductive Quantum Algebra Magnetic Conscience Operators