International Journal of Applied Electromagnetics and Mechanics - Volume 33, issue 1-2

Authors: Liu, Dong-Yao | Zhou, Yan-Huang

Article Type: Research Article

Abstract: The 2-dimensional unsteady expansion process of plasma jet ablated in capillary because of the discharging of pulse power is simulated with CE/SE (conservation element / solution element) scheme in this paper. The high resolution computational space-time CE/SE scheme is simplified and improved to solve the axisymmetric two dimensional Euler equations of the unsteady expansion process of ablation plasma jet in open air. The variation and distribution of pressure and velocity of ablation plasma jet in flow …field are illustrated and analysed. The shock wave and discontinuity of the jet are clearly depicted according to results of simulation, and simulating results are well agreement with experiment. Show more

Keywords: Plasma jet, simulation, CE/SE scheme

DOI: 10.3233/JAE-2010-1121

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 259-269, 2010

Authors: Ciric, Ioan R. | Hantila, Florea I. | Moraru, Augustin | Maricaru, Mihai

Article Type: Research Article

Abstract: By performing holes in a thin electromagnetic shield, its weight and price can be reduced, without practically changing the shielding efficiency for certain geometries and frequencies. A new method for solving the integral equation of the surface current density in thin shields with holes is applied, where the current density is represented by a linear combination of specialized surface vector functions associated with the interior nodes of the discretization mesh and with the sets of nodes …on each hole contour. A Galerkin technique is applied to determine the scalar coefficients of these functions. The magnetic flux density in the shielding zone is obtained accurately, in terms of exact analytical formulas, from these vector functions. Show more

Keywords: Shielding efficiency, current sheet integral equations, thin shields with holes

DOI: 10.3233/JAE-2010-1122

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 271-278, 2010

Authors: Zhao, Yanzhen | Chen, Feng | Kang, Bo | Ma, Xikui

Article Type: Research Article

Abstract: In this paper, the optimum design of round-wire dry-type air-core reactor is considered. An optimum design model is built based on the balance of three additional constraints, which is consist of layer resistance drop equalization, package temperature rise equalization and package height equalization. It is proved that the three additional constraints can not be simultaneously satisfied for a round-wire reactor when the number of packages is greater than 1. For this reason, the additional constraints balance …is proposed for the optimum design of a reactor. According to the optimum design model, a new hybrid genetic algorithm combined with simplex method is introduced and studied in detail. The hybrid genetic algorithm can enhance the local searching ability and improve the optimization efficiency. Finally, the proposed method is applied to the optimum design of dry-type air-core reactor, and a satisfied result is obtained. Show more

Keywords: Optimum design, dry-type air-core reactor, additional constraints, hybrid genetic algorithm

DOI: 10.3233/JAE-2010-1123

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 279-284, 2010

Authors: Yu, Byoung-Hun | Lee, Won-Yong | Kim, Byung-Taek

Article Type: Research Article

Abstract: This paper deals with starting characteristics of a single-phase line start permanent magnet (LSPM) motor considering nonlinear properties of magnetic materials. To take into account nonlinearity of iron core according to operating states, d-and q-axis inductances are calculated by magneto-static FE-analysis for various currents. The calculated dq-axis inductances are used in the equivalent circuit of a single-phase LSPM motor and dynamic performances are analyzed with 4th order Rung-Kutta method. The results are …compared with time-step FE-analysis results and the effects of nonlinearity are discussed. Show more

Keywords: Finite element method, line-start, nonlinear, permanent magnet, starting characteristic

DOI: 10.3233/JAE-2010-1124

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 285-292, 2010

Authors: Yan, Rongge | Yang, Qingxin | Yang, Wenrong | Hou, Shuping | Liu, Fugui | Yan, Weili

Article Type: Research Article

Abstract: This paper studies the dynamic response performance of giant magnetostrictive acceleration sensors. A magneto-mechanical strongly coupled dynamic model is presented, which is calculated by means of the finite element method. According to the proposed model, the time characteristic of the induced voltage for the acceleration sensor built with rare earth giant magnetostrictive alloy is calculated. A comparison between the calculated results and measured ones has been carried out to examine the validity of the …proposed dynamic model and the FE implementation. It is found that they are in an agreement. This indicates that the proposed FE model can reflect dynamic response performance of giant magnetostrictive acceleration sensors. Show more

Keywords: Giant magnetostrictive acceleration sensors, dynamic model, finite element method

DOI: 10.3233/JAE-2010-1125

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 293-298, 2010

Authors: Park, Seong-Cheol | Kim, Dae-Kyong | Kim, Byung-Taek

Article Type: Research Article

Abstract: This paper deals with design and characteristic analysis of a pole changing written-pole motor (WPM), which is a synchronous motor with self-starting ability. The winding configuration is deliberately determined to get a pole-changing function, and it is confirmed by FEA with time step method. In addition during operation of the exciter, the characteristics of magnetization of magnet and synchronization of a rotor are also analyzed.

Keywords: Pole-changing, self-start, synchronous motor, written-pole motor

DOI: 10.3233/JAE-2010-1126

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 299-306, 2010

Authors: Zhang, Fang | Tang, Zhanghong | Dun, Yueqin | Yuan, Jiansheng

Article Type: Research Article

Abstract: An approach for solving the electrostatic field in 3-D unbounded domains is introduced in this paper, which is the combination of the finite element method (FEM) and the Kelvin transformation. The principle of this method is dividing the whole infinite region into two parts by a spherical surface. In the inner part with a sphere as the boundary, the ordinary finite element method is employed. As for the outer open-boundary part, the approach first transforms it …into a finite closed domain that is of the sphere as the boundary, in which the transmuted FEM is used. It is allowed that the exterior open-boundary part is of non-uniform medium, such as unlimited domains or different shapes with different materials whose interfaces might extend to infinity. Show more

Keywords: Electrostatic field, FEM, grounding, Kelvin transformation

DOI: 10.3233/JAE-2010-1127

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 307-312, 2010

Authors: Seo, Jang-Ho | Jung, Hyun-Kyo

Article Type: Research Article

Abstract: In this paper, we present a magneto-thermal model of an interior-permanent magnet synchronous machine (IPMSM) for electrical vehicle. Both magnetic and thermal field aspects are described based on 2-D finite element method (FEM). For accurate estimation of heat sources in the machine, we analyzed harmonic iron loss using variable loss coefficients and magnet loss in the electromagnetic field. In addition, we estimated convective exchange coefficient considering water-cooling system of the machine. Finally, …experimental results on 60 kW, 3600 rpm are reported and compared with the simulation results. Show more

Keywords: Electric vehicle, finite element method, iron loss, interior permanent magnet synchronous machine, water-cooling system.

DOI: 10.3233/JAE-2010-1128

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 313-319, 2010

Authors: Wang, Yongqing | Li, Lei | Li, Xiaojia | Wang, Haizhou

Article Type: Research Article

Abstract: In the condition of certain electromagnetic levitation coil and spherical sample, according to the expressions of levitation force and absorbed power in magnetic field, the relationship between levitation force, absorbed power and high frequency power supply frequency is established in this paper. In addition, the effect of the power supply frequency on the levitation force of the coil and the absorbed power of the sample is analyzed, and the general rules of frequency parameter selection are …confirmed. Finally, a guiding role in the frequency selection of high frequency power supply in electromagnetic levitation melting is played. Show more

Keywords: Electromagnetic levitation melting, frequency, levitation force, absorbed power

DOI: 10.3233/JAE-2010-1129

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 321-327, 2010

Authors: Rondot, Loïc | Mazauric, Vincent | Ladas, Dimitrios

Article Type: Research Article

Abstract: In order to improve the finite element modeling of macroscopic eddy currents, a quadratic energy-based error criterion is derived from a thermodynamic description of electromagnetism. While the conservation of the electromagnetic power is assessed locally to highlight the ill-checked elements, the state functions provide the global convergence of the calculation within an adaptative procedure. The criterion is shown: suitable for 2D and 3D, independent of the formulation, supporting the body motion. A validation is …given on a Thomson's effect device. Show more

Keywords: Electromagnetism, eddy currents, error criterion, finite element method

DOI: 10.3233/JAE-2010-1130

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 329-333, 2010