International Journal of Applied Electromagnetics and Mechanics - Volume 35, issue 4

Authors: Lim, Jaewon | Hong, Sun-Ki | Jung, Hyun-Kyo

Article Type: Research Article

Abstract: This paper presents the development of a 5kw class tubular type linear generator. The two main characteristics of the generator, the back EMF and the cogging force, are calculated using the finite element method. To reduce the cogging force, the pole pitch modulation method and dummy teeth are adopted. The designed machine is simulated and manufactured for verification.

Keywords: Cogging force, free-piston engine, linear generator, tubular linear machine

DOI: 10.3233/JAE-2011-1334

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 4, pp. 231-240, 2011

Authors: Liu, Feng | Zhang, Huihui | Chang, Fuqing

Article Type: Research Article

Abstract: A lot of experiments have proved that the basic reason of the nonlinear and hysteresis constitutive curve in ferroelectric ceramics is domain switching. The microscopic domain switching behaviors of BaTiO_3 single crystals have been studied detailed. The forward and sideway motion of 180° domain wall has been measured by direct stroboscopic observation. The velocity expressions are given. In order to get the evolution equation of the volume fraction of domain switching, a square …domain switching model is developed according to the relationship between the domain wall velocity and applied electric field. The model is compared to available experimental data of BaTiO_3 single crystals. It turns out that the model can represent the typical nonlinear electromechanical coupling phenomena. The evolution equation of the volume fraction of domain switching is reasonably consistent with a previous phenomenological model. Furthermore the evolution equation based on microscopic domain motion can further improve the microscopic phenomenological model. Show more

Keywords: Ferroelectric, single crystal, constitutive, domain switching, the volume fraction of domain switching

DOI: 10.3233/JAE-2011-1335

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 4, pp. 241-248, 2011

Authors: Chiu, Chien-Ching | Sun, Chi-Hsien | Chang, Wan-Ling

Article Type: Research Article

Abstract: This paper reports a two dimensional time domain inverse scattering algorithm based upon the finite-difference time domain method for determining the shape of perfectly conducting cylinder. Finite difference time domain method (FDTD) is used to solve the scattering electromagnetic wave of a perfectly conducting cylinder. The inverse problem is resolved by an optimization approach and the global searching scheme asynchronous particle swarm optimization (APSO) is then employed to search the parameter space. By …properly processing the scattered field, some EM properties can be reconstructed. One is the location of the conducting cylinder, the others is the shape of the perfectly conducting cylinder. This method is tested by several numerical examples; numerical results indicate that the APSO outperforms the PSO in terms of reconstruction accuracy and convergence speed. Both techniques have been tested in the case of simulated measurements contaminated by additive white Gaussian noise. Show more

Keywords: Index terms – inverse scattering, time domain, FDTD, subgridding finite difference time domain, asynchronous particle swarm optimization (APSO), cubic-spline

DOI: 10.3233/JAE-2011-1336

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 4, pp. 249-261, 2011

Authors: Zhang, Jian-Ping | Hu, Dan-Mei | Dai, Yong-Xia | Ding, Quan-Fei

Article Type: Research Article

Abstract: This paper describes a strongly coupled calculation procedure for the particle dynamics in electrostatic precipitators (ESP) subjected to the applied magnetic field with the statistical particle size distribution taken into account. The turbulent gas flow and the particle motion under external forces are modeled by using the commercial computational fluid dynamics (CFD) code FLUENT. Numerical calculations for the gas flow are carried out by solving the Reynolds-averaged Navier-Stokes equations and turbulence is modeled using …the k − ε turbulence model. An additional source term, which is obtained by solving a coupled system of the electromagnetic field and charge transport equations, is added to the gas flow equation to capture the effect of electromagnetic field. Discrete Phase Model (DPM) is employed to achieve the simulation of the particle phase. Different kinds of particles which follow Rosin-Rammler distribution were simulated under different conditions, and the influence of magnetic field density on the capture of fine particle was investigated. In order to show the dust removal effect, the collection efficiency and the escaped particle size distribution were discussed in case of different applied magnetic fields. The particles trajectories inside the ESP were also given under the effects of both aerodynamic and electromagnetic forces. Numerical results indicate that the collection efficiency increases with the increase of applied magnetic field, that the particles trajectory are more visible to the direction of dust collection plate, and that the collection efficiency varies smoothly when the applied magnetic field is up to a certain value. Furthermore, the average diameter of escaping particles decreases and the dispersion for dust particles in different size increases with applied magnetic field increasing, and particle sizes is linearly decreasing with magnetic field before the particle reaches a certain size. Show more

Keywords: Applied magnetic field, electrostatic precipitation, gas-solid two-phase flow, collection efficiency, particle trajectories

DOI: 10.3233/JAE-2011-1337

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 4, pp. 263-279, 2011

Authors: Moghadam, Amir Ali Amiri | Torabi, Keivan | Moavenian, Majid

Article Type: Research Article

Abstract: Conjugated polymer actuators can be employed to achieve micro scale precision positioning, having a wide range of application including biomimetic robots, and biomedical devices. They can operate with low voltage while producing large displacement, in comparison to robotic joints, they do not have friction or backlash, but on the other hand, they have complicated electro-chemo-mechanical dynamics, which makes accurate and robust control of the actuator difficult. There has been extensive research on modeling the …electrochemical dynamics of polypyrrole bending actuators. However the mechanical dynamics modeling of actuator remains to be unexplored. In this paper finite element modeling and robust control of fast trilayer polypyrrole bending actuators is proposed. In the modeling part the infinite-dimensional admittance model of actuator will be replaced with a family of linear uncertain transfer functions based on Golubev Method. Further model development will take into account the proper mechanical dynamics, which is essential, when using fast conducting polymer actuators. The purposed modeling approach will be validated based on the existing experimental data. In the controlling part the robust control QFT will be applied to control the highly uncertain dynamics of the conjugated polymer actuators while the actuator carrying variable tip loadings. Finally the analysis of design shows that QFT controller has consistent and robust tracking performance. Show more

Keywords: Fast conjugated polymer actuators, Polypyrrole, FEM, Uncertainty, QFT, Active vibration control

DOI: 10.3233/JAE-2011-1359

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 4, pp. 281-305, 2011

Article Type: Correction

Abstract: Erratum to [International Journal of Applied Electromagnetics and Mechanics 35(2), 2011, 93-101], DOI 10.3233/JAE-2011-1323. http://iospress.metapress.com/content/l4t065874q635044/.

DOI: 10.3233/JAE-2011-1365

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 4, pp. 307-307, 2011

Article Type: Other

Abstract: Author Index to Volume 35 (2011)

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 35, no. 4, pp. 309-311, 2011