International Journal of Applied Electromagnetics and Mechanics - Volume 40, issue 4

Authors: Xiong, Run | Chen, Bin | Cai, Zhaoyang | Chen, Qiang

Article Type: Research Article

Abstract: A numerically efficient method for the finite-difference time-domain (FDTD) analysis of shielding effectiveness (SE) of large shielding enclosures has been proposed in this paper. FDTD has been widely applied in the SE analysis, but it is difficult to analyze the SE using the standard FDTD method when large shielding enclosures with thin-slots are involved. To model the narrow apertures without involving too much memory occupation, the thin-slot formalism is adopted. The parallel implementation is induced into …the simulation in order to overcome the limitation of a single processor's memory. To decrease the simulating time, windowing technique is used in the SE analysis. By using these artifices, the FDTD analysis of large shielding enclosures can be carried out efficiently. Show more

Keywords: Finite-difference time-domain method (FDTD), windowing technique, parallel implementation, shielding effectiveness (SE)

DOI: 10.3233/JAE-2012-1589

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 40, no. 4, pp. 251-258, 2012

Authors: Lin, Chin E. | Huang, Wei Cheng

Article Type: Research Article

Abstract: This paper presents an enforced fuzzy logic control (EFLC) implementation on a ball and plate system (B&P) for dynamic control verifications. A two degree-of-freedom (DOF) platform is constructed for experiments using hybrid magnetic suspension (MS) actuators. The EFLC adds an enforcing rule to buffer the running ball to approach the target. It reduces the overshoot, shortens the settling time, and improves the overall performance significantly. The mathematical model of the ball and plate operation is …derived through the Euler-Lagrange equation. Using a commercial touch panel as position sensor, a microprocessor controller is implemented on the proposed system to generated Pulse Width Modulation (PWM) control signals to activate the MS actuators. The tests verify the random position tracking and trajectory tracking performance on the MS B&P with different conditions. This proposed system could be applied to prevent turn over as an active device in transportation field. Show more

Keywords: Ball and plate system, enforced fuzzy logic control, magnetic suspension actuator, sensor feedback

DOI: 10.3233/JAE-2012-1590

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 40, no. 4, pp. 259-281, 2012

Authors: Dong, Jian-Feng | Li, Jie

Article Type: Research Article

Abstract: The characteristics of guided modes in the circular waveguide filled with uniaxial chiral medium have been investigated. The dispersion equation of guided modes is derived. The dispersion curves, energy flux of guided modes for three kinds of uniaxial chiral media are presented. Abnormal dispersion characteristics and negative energy flux are found, i.e., backward wave is supported in the uniaxial chiral waveguide. It is also shown that the ± m order guided modes have the same propagation …constants. Show more

Keywords: Uniaxial chiral medium, chiral waveguide, circular waveguide, energy flux

DOI: 10.3233/JAE-2012-1591

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 40, no. 4, pp. 283-292, 2012

Authors: Kumar, Satendra | Desai and, S.V. | Chakravarthy, D.P.

Article Type: Research Article

Abstract: The paper describes the procedure for selection of electromagnetic parameters which govern the Electromagnetic Welding (EMW) process. EMW is a specific application of electromagnetic Forming (EMF). The metallic bodies get deformed and eventually collide to get welded. Hence it is classified as deformation bond. It is observed that the parameters such as input electrical energy, ringing frequency, coil geometry, coil conductor section, job material and it's configuration play a very important role in achieving the welding. …In addition to this, the separation distance between the two colliding bodies (plates in the present case) is also a crucial parameter. These parameters together decide the resultant collision velocity. The collision velocity in turn decides the strength of weld joint. The procedure is formulated based on computational and experimental observations as applied to 1 and 2 mm thick aluminium plates. This procedure could be extended for other materials and their combinations (such as similar or dissimilar and of different dimensions). Show more

DOI: 10.3233/JAE-2012-1592

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 40, no. 4, pp. 293-300, 2012

Authors: Hassan, Muhammad Haseeb | Junaid Mughal, Muhammad | Farooqi, Abdul Razzaq

Article Type: Research Article

Abstract: The present study deals with the propagation of electromagnetic fields and power in a circular waveguide, with D'B'-boundary conditions, internally coated with chiral-nihility medium. The electromagnetic fields inside the two layer circular waveguide defined by D'B'-boundary conditions, with one layer containing free space while other layer containing chiral-nihility medium, is investigated. D'B'-boundary conditions require vanishing of derivatives of the normal field components of D and B vectors, hence named as D'B'-boundary conditions. …It has been investigated that unlike to the chiral-nihility coated perfect electromagnetic conductor (PEC) waveguide, there is a non-zero power transfer in chiral-nihility region in waveguide with D'B' boundary conditions. Show more

Keywords: D'B' boundary conditions, chiral-nihility medium, circular waveguide

DOI: 10.3233/JAE-2012-1593

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 40, no. 4, pp. 301-308, 2012

Authors: Moghaddam, Saied

Article Type: Research Article

Abstract: An analytical solution is found for equations of AC and DC-operated MHD micropump with circular channel. The kind of fluid is Newtonian and the flow generated by the Lorentz force is assumed to be laminar, unidirectional, and one-dimensional. The effect of Hartman number and radius is studied on the velocity and volumetric flow rate profiles and a relation for optimum Hartman number and radius which causing maximum volumetric flow rate is found. Finally DC-operated MHD micropump …is compared with AC-operated. Show more

Keywords: MHD micropump, circular channel, hartmann number, lorentz force, analytical solution

DOI: 10.3233/JAE-2012-1594

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 40, no. 4, pp. 309-322 , 2012

Authors: Gong, Fei | Weng, Chun-Sheng

Article Type: Research Article

Abstract: In this paper we investigate the influence of different rail coatings on melt-wave erosion (MWE) in block armatures. A two-dimensional numerical model is developed and the finite difference method is used to simulate the transient evolution of MWE. The results of numerical calculations show a local concentration of current and joule heating at the interface, and MWE occurs at the trailing corner of the block armature. Five different pure metals are used as the rail coatings …to improve the launching performance of the railgun. Important electrical parameters of coatings are analyzed through comparing the axial erosion distance and the vertical gap thickness. It is observed that the coating materials with a higher electrical conductivity than that of rail material are helpful to delay the spread of MWE. The results are inspiring and contribute to apply the rail coatings to solid-armature railguns. Show more

Keywords: Solid-armature railguns, rail coatings, velocity skin effect, melt-wave erosion, finite difference

DOI: 10.3233/JAE-2012-1595

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 40, no. 4, pp. 323-331, 2012

Authors: Zhang, Rong | Ma, Peng | Li, Qing Hui

Article Type: Research Article

Abstract: Applying the plane strain approach, the flux-pinning-induced magnetostriction of a transversely isotropic functionally graded long rectangular superconducting slab is studied analytically. The effects of both the applied magnetic field and elastic property distribution on magnetostriction for different symmetric cases of the slab are shown graphically and discussed in detail. Results presented in this paper should have potential applications to the design of superconducting materials and devices.

Keywords: Magnetostriction, superconductor, transversely isotropic material, functionally graded slab

DOI: 10.3233/JAE-2012-1596

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 40, no. 4, pp. 333-340, 2012

Authors: Wang, Qingping | Pei, Xuebing | Wang, Qi | Jiang, Shenglin

Article Type: Research Article

Abstract: A finite model based on the classical laminated plate theory is presented for the unimorph piezoelectric cantilever. The formulations of static and dynamic analysis are derived from the variation principle. Three material parameter matrices of the PZT are taken into account in the present model. The static analysis of the piezoelectric cantilever is performed to investigate the influence of the geometric parameters on the output voltage, and model analysis is selected to determine the natural frequency …and eigenmodes. To validate the simulation results, an experiment on a unimorph cantilver with brass substrate was carried out. The experiment results were found to be in good agreement with the simulation results. The results indicate that the finite model can be beneficial to designing ideal piezoelectric energy harvesting devices. Show more

Keywords: Finite element model, piezoelectric cantilever, energy harvesting, open-circuit voltage

DOI: 10.3233/JAE-2012-1597

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 40, no. 4, pp. 341-351, 2012

Article Type: Other

Abstract: Author Index Volume 40 (2012)

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 40, no. 4, pp. 353-356, 2012