International Journal of Applied Electromagnetics and Mechanics - Volume 43, issue 3

Authors: Hu, Chao | Sun, Yue | Wang, Zhihui | Tang, Chunsen | Xiong, Qingyu

Article Type: Research Article

Abstract: Remote and high power Inductive Power Transfer (IPT) system has proved its capability as a power source for Electric Vehicles' (Evs') wireless charging. The performance of magnetic coupler is the major factor which limits the transmission distance, power levels and the feasibility of IPT system. Maximum output power (P_m ) is one of the most important parameters for these systems. By analyzing the correlative factors which affect P_m , the result reveals that …P_m is inversely proportional with magnetic flux or uncompensated power of power receiving coils. New ferrite core matrices array has been designed as the basic component for magnetic coupler, which allows for a variety of winding ways according to the actual application. The result of a 3D finite element model shows that P_m produced by the proposed winding ways is much higher than that of air core, and this could be a solution to satisfy the requirements from power transmission in wireless charging. Show more

Keywords: Inductive Power Transfer (IPT), Electro Vehicle (EV), magnetic coupler, ferrite array, wireless charging

DOI: 10.3233/JAE-131693

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 3, pp. 195-205, 2013

Authors: Angiulli, G. | De Carlo, D. | Isernia, T.

Article Type: Research Article

Abstract: In this paper, a sensitivity study aimed to evaluate how the field scattered by a malignant tumor is influenced by the operation frequency f_o of the microwave tomographic diagnostic system, and by the permittivity {ϵ}_f of the matching fluid, is presented. The study has been carried out exploiting accurate anthropomorphic numerical breast phantoms in conjunction with the Contrast Source Integral Equation. Numerical results provide useful insights towards an optimal choice …of these parameters able to enhance the cancer's detectability. Show more

Keywords: Breast cancer, Contrast Source Integral Equation, microwave imaging

DOI: 10.3233/JAE-131694

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 3, pp. 207-214, 2013

Authors: Ma, Hongzhong | Wang, Qingyan | Ju, Ping

Article Type: Research Article

Abstract: To solve the problem of heat and friction existing in weight bearing of the hydraulic generator, a new type of magnetic levitation devices is proposed. The devices consist of electromagnetic and permanent magnetic levitation, which share together most of the hydraulic generator rotor weight to reduce axial load on thrust bearing. The permanent magnetic levitation is performed by new repulsive ring Halbach arrays. The new Halbach arrays are analyzed by using magnetic potential equations and superposition …principle, and the magnetic flux density formulas are obtained. The formula results are verified by FEM. By further study of 3D model simulation analysis, it is confirmed that the new repulsive ring Halbach arrays can reach the design goal on actual working conditions. Show more

Keywords: Hydraulic generator, magnetic levitation, Halbach array, repulsion

DOI: 10.3233/JAE-131695

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 3, pp. 215-226, 2013

Authors: Raval, Falguni | Kosta, Y.P. | Joshi, Harshita

Article Type: Research Article

Abstract: In this paper, dual-band microstrip antenna with complementary split ring resonator is presented. The designs are based on the metamaterial property of the complementary split ring resonator. A simple dual-band antenna can be realized by etching single CSRR in the ground plane of a conventional patch antenna. The proposed antenna shows good performances at both resonant frequencies. The CSRR in the ground plane makes a major contribution to the first operating band, but it has a …minor effect on the second operating band. The simulation results are analyzed and compared with the measured results, which shows that there is a good agreement between them. Show more

Keywords: Microstrip circular patch antenna, split ring resonator (SRR), complementary split ring resonator (CSRR), modified ground plane, metamaterial

DOI: 10.3233/JAE-131696

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 3, pp. 227-235, 2013

Authors: Vasic, Dejan | Costa, François

Article Type: Research Article

Abstract: A piezoelectric energy harvester with a multi-mode dynamic magnifier is proposed and modeled in this paper. The dynamic magnifier consists of an intermediate beam with a tip mass, which is placed between the fixed end of the energy harvesting beam and the vibrating base structure. The piezoelectric element is bounded to the harvesting beam to harvest the vibration energy. With proper choice of the design parameters of the magnifier, the harvested electric power can be significantly …increased due to the bandwidth extension, which enables energy harvesting from the ambient vibration in a larger range of frequency. Theoretical analysis is carried out with 4 × 4 chain matrix representation. Numerical examples are presented to illustrate the merits of the dynamic magnifier in comparison with the conventional piezoelectric energy harvesters. The results show that electric power produced by the harvesting beam is amplified for efficient energy harvesting over a broader frequency range. Show more

Keywords: Piezoelectric energy harvesting, dynamic magnifier

DOI: 10.3233/JAE-131697

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 3, pp. 237-255, 2013

Authors: Zhao, Pengcheng | Liao, Cheng | Lin, Wenbin

Article Type: Research Article

Abstract: Simulations of the interaction of high-power microwave (HPM) pulses with air-SF_6 mixtures at high pressure in the fluid model are presented, where various reaction sets of air and SF_6 are taken into account. Introducing a small amount of SF_6 in air can drastically increase the breakdown threshold. At a higher pressure or for a larger pulse width, the breakdown threshold increases more significantly as the percentage of SF_6 …in the mixture increases. The amplitude of the transmitted pulse in the air breakdown decreases with time and its width is shortened. Due to the higher attachment frequencies in the air-SF_6 mixture and SF_6 , the amplitude of the transmitted pulse keeps almost unchanged after it experiences a short-time attenuation, and the pulse width is not strongly influenced. Most of the energy loss of the transmitted pulse in the gas breakdown propagates in the opposite direction, and the rest of energy loss is due to electron heating. The accuracy of the fluid model is verified by experimental results. Show more

Keywords: High-power microwave, propagation, gas breakdown, fluid model

DOI: 10.3233/JAE-131698

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 3, pp. 257-269, 2013

Authors: Amiri, N. | Forooraghi, K. | Atlasbaf, Z.

Article Type: Research Article

Abstract: In this paper two novel left-handed composite metamaterials consisting of SRRs, wire and single sided S-shaped resonators are proposed. One of them is a reduced-size resonator which uses superposition hypothesis to achieve adjacent resonances for a much broader negative refraction passband. The other is a modified planar structure with improved electromagnetic coupling and reduced electrical size. Both structures are truly matched to free space in almost whole left-handed frequency band. It will be shown that these …metamaterials are robust to the fabrication errors of misalignment printing on both sides of the substrate. The superior performance of these structures are investigated numerically and experimentally and compared with the other split ring resonators. Wedge shape simulation and experimental results confirm the left-handed passband. Show more

Keywords: Metamaterial, double Negative, near zero index, left-handed material

DOI: 10.3233/JAE-131699

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 3, pp. 271-281, 2013

Authors: Sun, Tiger | Peng, Xianghe | Li, Jingzhi | Feng, Chao

Article Type: Research Article

Abstract: More attentions have been paid to Magnetorheological fluid, which is a kind of new functional materials. An elegant device is designed for the test of the mechanical properties of Magnetorheological fluid, and the mechanical properties of ten samples of Magnetorheological fluid are tested with the device. In the experimental investigation, we choose ten samples of Magnetorheological fluid to analyze and obtain the material parameters with the testing device. The effects of the typical influencing factors, such …as magnetic induction intensity, ferromagnetic particle volume fraction, base solutions, temperature, shear strain rate, response time, sedimentation stability, yield shear stress, viscosity and zero-field viscosity, etc., are investigated. This work proves that Magnetorheological fluid is reliable and practical through experimental results. We welcome warmly the relevant experts and scholars to exchange and guide further. Show more

Keywords: Magnetorheological fluid, experimental testing device, samples, experiment, magnetic field

DOI: 10.3233/JAE-131700

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 3, pp. 283-292, 2013

Authors: Zhang, Dongli | Wu, Meixian | Wang, Zhaoba | Chen, Zhenmao

Article Type: Research Article

Abstract: In order to make an effective on-line thickness measurement of thick coating in hemispherical steel shells, a strategy using combined laser and eddy current (EC) sensors based on displacement differential method was proposed. To enhance the measuring precision, an EC displacement sensor with large test range was adopted and the effect of shell curvature on its output was reduced by applying the polynomial curve fitting. Its feasibility was verified by experimental results.

Keywords: Stainless steel, coatings, eddy current sensor, laser sensor, condition monitoring

DOI: 10.3233/JAE-131701

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 3, pp. 293-300, 2013

Authors: Feng, W.J. | Li, Q.H.

Article Type: Research Article

Abstract: In this paper, the distributions of the stresses induced by flux pinning in a superconducting cylinder with a concentric elliptic hole are investigated. First, the distribution function of the flux density during field descent after field cooling process is given by adopting the exponent model for the critical current state. Then, the flux pinning forces are further derived. Finally, numerous numerical results are plotted by using finite element method and are analyzed in detail. Numerical results …show that for the superconducting cylinder with an elliptic hole, along the direction of the long axis, the phenomenon of stress concentration for hoop stress occurs at the hole edge, and that in general, the radial stress changes rapidly near the hole edge. In addition, both the shape of the hole and the model parameter of the present critical state model have important and different effects on the stress distributions. Results presented in this paper should have potential applications to the design of superconducting materials. Show more

Keywords: Stress, flux pinning, superconducting cylinder, exponent model, elliptic hole

DOI: 10.3233/JAE-131702

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 3, pp. 301-309, 2013