International Journal of Applied Electromagnetics and Mechanics - Volume 17, issue 4

Authors: Cho, Han-Sam | Im, Chang-Hwan | Jung, Hyun-Kyo | Chung, Tae-Kyung

Article Type: Research Article

Abstract: The characteristics of a three-phase synchronous permanent magnet planar motor (SPMPM) are analyzed numerically using a volume integral equation method (VIEM). The mover dimensions are optimized to minimize the detent force. The back-EMF waveform is calculated and the coil dimensions are optimized to set the back-EMF constant to a constant value regardless of mover positions. All simulation results are verified by a comparison with experimental results.

Keywords: back-EMF constant, detent force, planar motor, volume integral equation method (VIEM)

DOI: 10.3233/JAE-2003-264

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 17, no. 4, pp. 259-269, 2003

Authors: Dost, S. | Liu, Y. | Lent, B. | Redden, R.F.

Article Type: Research Article

Abstract: A numerical simulation study was carried out for the growth of CdTe crystals by the Travelling Heater Method to examine the effects of applied stationary and rotating magnetic fields, and also small non-uniformities in the stationary magnetic field. A strong stationary field is applied to suppress the natural convection in the solution zone, and a small but rotating magnetic field is considered for better mixing in the horizontal plane. The spatial distribution of the stationary field …is almost uniform before the furnace and the growth system are lowered into the magnet opening. However, the field uniformity may be altered by the presence of the growth system. In order to determine the effect of such field non-uniformities, small magnetic body force components are considered in the model. Results show that higher stationary field levels are better in suppressing convection in the solution, but enhance the compositional non-uniformity in the solution. Small but unintentional non-uniformities in the stationary magnetic field also enhance compositional non-uniformity. A rotating magnetic field, on the other hand, is beneficial for mixing in the horizontal plane, and reduces the compositional non-uniformity in the solution. Mixing is enhanced at higher rotating magnetic field frequencies. Show more

DOI: 10.3233/JAE-2003-265

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 17, no. 4, pp. 271-288, 2003

Authors: Yang, J.S. | Fang, H.Y.

Article Type: Research Article

Abstract: A piezoelectric gyroscope consisting of a concentrated mass connected to two orthogonal piezoelectric rods in extensional vibrations is proposed. A simple theoretical model is constructed for the proposed gyroscope, which allows complete analytical analysis. Simple close form solutions for free and forced vibrations are obtained. Resonant frequencies, output voltage and current as well as their dependence on various geometric and physical parameters are examined.

DOI: 10.3233/JAE-2003-266

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 17, no. 4, pp. 289-300, 2003

Authors: Chiu, Chien-Ching | Li, Ching-Lieh | Ho, Cheng-Shun

Article Type: Research Article

Abstract: The image reconstruction of a two-dimensional periodic imperfect conductor by the genetic algorithm is investigated. A periodic imperfectly conducting cylinder of unknown periodic length, shape and conductivity scatters the incident wave in free space and the scattered field is recorded outside. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equations is derived and the imaging problem is reformulated into an optimization one. The genetic algorithm is then employed to …find the global extreme solution of the object function. As a result, the periodic length, the shape and the conductivity of the conductor can be de-embedded. Numerical results demonstrate that even in the presence of noise, good reconstruction can be obtained. Show more

DOI: 10.3233/JAE-2003-267

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 17, no. 4, pp. 301-311, 2003