International Journal of Applied Electromagnetics and Mechanics - Volume 28, issue 3

Authors: Hillion, Pïerre

Article Type: Research Article

Abstract: We analyse the harmonic plane wave propagation in a anisotropic chiral medium characterized by a symmetric permittivity tensor, scalar permeability and scalar chiraliry weak enough to make negligible its nonlinear effects. The Fresnel equation is first discussed to get the refractive indices in the two directions of propagation. Then, the propagation of harmonic plane waves is investigated in biaxial and uniaxial anisotropic chiral media as well as the reflection of such a wave on these media. …Three Appendices giving the explicit form of the electromagnetic field components in anisotropic chiral media complete the paper. Show more

Keywords: Anisotropy, chirality, permittivity tensor, plane wave propagation

DOI: 10.3233/JAE-2008-943

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 3, pp. 337-350, 2008

Authors: Xu, Lizhong | Hao, Xiuhong

Article Type: Research Article

Abstract: In this paper, the equations of the electromagnetic forces between planet and worm or stator are presented. The electromagnetic forces are divided into static component and nonlinear ones, and then the nonlinear dynamic equations of the drive are given. By method of perturbation, nonlinear forced vibrations for the drive system are discussed. The changes of the vibrating magnitudes and vibrating frequency along with nonlinear parameter are given. A number of useful results are obtained. Results show: …as nonlinear parameter increases, the natural frequency of the drive system change obviously, and the vibrating magnitudes change slightly; It is enough that only the first order nonlinear item is considered; the real nonlinear forced vibrations for the drive system are multi-mode coupled vibrations and for rotational and translational vibrations of the planet, or rotational vibration of the rotor, unstable periodic vibrations occur; change curves of the vibrating magnitudes along with exciting frequency bend toward the direction of the exciting frequency increase, and above changes are influenced by drive parameters obviously. Show more

Keywords: Toroidal drive, electromechanical integrated, nonlinear dynamics, forced vibration

DOI: 10.3233/JAE-2008-944

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 3, pp. 351-369, 2008

Authors: Popa, N.C. | Siblini, A. | Rousseau, J.J. | Blanc-Mignon, Marie-Françoise | Payet-Gervy, Beatrice | Bayard, B. | Nader, C.

Article Type: Research Article

Abstract: The paper investigates the numerical calculation of the electrical coils belonging to the inductive transducers with magnetic fluids for inclinations and aerodynamic measurements. One way to improve the construction of these transducers is to increase the electrical frequency for their coils. In this case, the thickness of the coils can be reduced by a large amount. The paper presents a numerical model for calculating the inductance of these ultra thin coils versus the level of the …magnetic fluid core, the geometrical dimensions, and the magnetic properties of materials. Show more

Keywords: Ferrofluids, magnetic fluids, transducers, aerodynamics measurements, computer simulation, ferromagnetism

DOI: 10.3233/JAE-2008-947

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 3, pp. 371-378, 2008

Authors: Rho, Jong-Seok | Kwak, Sang-Yeop | Chung, Tae-Kyung | Jung, Hyun-Kyo

Article Type: Research Article

Abstract: In this paper, we report on our study of a Nano Positioning Actuator (NPA), which uses an impact/inchworm mechanism. Many kinds of similar precise positioning actuators, which use the same working mechanism, are being and have been proposed by many researchers for several decades. But, the characteristic analysis and design method of the NPA has not been proposed yet. Also, the characteristic analysis and design methods of similar machines were approximate and ineffective. Hence, …we present in this paper an analysis methodology for the NPA using the 3D FEM combined with an analytic method, shedding light on the complex working mechanism, and taking all effective components into consideration for an exact and effective characteristic analysis of the NPA and similar machines. In this study, the mechanical system and the driving circuit of an NPA were prototyped. Finally, the effectiveness of an NPA, the reasonableness of a clarified complex working mechanism, and the adequacy of the proposed analysis method were validated by experimental data. Show more

Keywords: Actuator, finite element method, impact mechanism, inchworm mechanism, nano, piezoelectric

DOI: 10.3233/JAE-2008-945

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 3, pp. 379-394, 2008

Authors: Carrillo, E.

Article Type: Research Article

Abstract: A dimensionless analysis of eddy current distribution on massive conductors was undertaken, using configurations for two excitation sources co-axial to a cylindrical induction device: a solenoidal type, as found in most coreless furnaces, and an axial type, similar to that used in induction motors. The mathematical model is based on a one-dimension solution of the electromagnetic diffusion equation in an infinitely long cylinder utilizing the Newton shooting method. The simulated electromagnetic performance is compared …for both configurations for a minimum in either the operational frequency or the size of a given induction heating system. The theoretical results show that workpieces powered by single-phase axial winding, featuring one pair of magnetic poles, release ohmic losses equivalent to the solenoidal counterpart using half of its frequency or the square root of its radius. Show more

Keywords: Eddy currents, induction heating optimization, transverse-flux induction heating, shielding parameter

DOI: 10.3233/JAE-2008-993

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 3, pp. 395-412, 2008