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

Authors: Mazauric, Vincent | Drouineau, Mathilde | Rondot, Loïc

Article Type: Research Article

Abstract: A new approach to face the problem of dynamic hysteresis and assess extra-losses in soft magnetic materials is investigated. Thanks to a spatial averaging technique and a variational principle, a dedicated formulation is derived. It takes into account microscopic magnetization mechanisms and domain wall motion-induced Joule losses. A validation is proposed by assessing time-harmonic losses on a 2D-Pry and Bean iron sheet. Discussion includes also a confrontation with the delayed diffusion model and Bertotti's …experiments. Show more

Keywords: Electromagnetism, magnetic materials, transient formulations, eddy currents, dynamic hysteresis, anomalous losses

DOI: 10.3233/JAE-2010-1101

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 95-101, 2010

Authors: Yamaguchi, K. | Suzuki, K. | Nittono, O. | Takagi, T.

Article Type: Research Article

Abstract: Domain wall displacements were simulated using Monte Carlo method with a conventional crystal anisotropy for cylindrical and spherical micro magnetic clusters having a bcc crystal structure. The anisotropy properties of magnetization processes show qualitatively good correspondences with the experimental results for bcc iron. The simulations also demonstrate behaviors of their domain wall displacements and rotation magnetizations on the magnetization processes. Moreover the simulation was applied for a deformed cylindrical cluster elongated 1.01 …times along the [010] direction and the result shows the domain wall displacement has a two steps process. Show more

Keywords: Magnetic anisotropy, magnetic domains, magnetic hysteresis, Monte Carlo methods

DOI: 10.3233/JAE-2010-1102

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 103-110, 2010

Authors: Wang, Jiang-Bo | LI, Yao-Hua | Yan, Lu-Guang

Article Type: Research Article

Abstract: Eddy current braking systems are used in order to avoid the limit of mechanical brake. The eddy current braking system with dc-excited magnet needs the power supply and has the consequent power losses. The braking system using permanent magnets can obtain high efficiency due to no power losses. The magnetic flux density of permanent magnet Halbach array is stronger than that of conventional permanent magnet array. Further more Halbach array is of one-sided flux structure and …has self-shielding property, magnetic field of one side is enhanced and the other side is weakened. Hence applying linear Halbach array to eddy current brake system is studied. Analytical method is used to analyze the electromagnetic mechanism in eddy current brake and the braking force equation is deduced. An experimental system is designed, the braking force equation is verified with the experimental result, and the result of experiment is analyzed. Show more

Keywords: Linear Halbach array, eddy current brake, braking force

DOI: 10.3233/JAE-2010-1103

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 111-118, 2010

Authors: Machado, José Márcio | Shiyou, Yang

Article Type: Research Article

Abstract: This work presents simulations of the Electrofluid Dynamic energy conversion process in slender channel devices having very small particles (in both micro and nano scales) as charge carriers. Solutions are discussed for a system composed by coupled differential equations, which includes the equation for the total current along the channel, the equations for total energy and momentum of the mixture (gas and solid particles), the continuity equation and the equations for energy and momentum of a …single particle. Results for suspended particles of higher diameters have been previously published in the Literature, but the simulations here presented exhibit an appreciable increase in the values for output currents. Show more

Keywords: EFD energy conversion, particulate systems, nanoparticles

DOI: 10.3233/JAE-2010-1104

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 119-125, 2010

Authors: Deng, Xianming | Wang, Lei | Zhang, Jiamin | Wang, Kang

Article Type: Research Article

Abstract: In order to solve problems of complicated structure and huge volume of synchronous machine (SM), this paper presents a brushless synchronous machine with the structure of single stator core and single rotor core. Power windings and excitation windings of stator are laid in the same stator core. Correspondingly, DC excitation windings and AC windings of rotor are laid in the same rotor core, fixed in the machine's rotor by the rotating rectifier which is formed of …commutation diodes. Magnetic field of the new structure machine is analyzed and calculated by ANSYS. The results show that the designed brushless synchronous machine has characteristics such as simple structure and superior performance. Therefore, it has a good application prospect. Show more

Keywords: Brushless synchronous machine, magnetic field analysis, working principle, brushless excitation system

DOI: 10.3233/JAE-2010-1105

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 127-133, 2010

Authors: Hasegawa, Hitoshi | Kashiwagi, Takayuki | Sakamoto, Yasuaki | Sasakawa, Takashi

Article Type: Research Article

Abstract: This paper describes the realization of the magnet rotor type non-contact transformer that is possible to transmit electric power and a torque by non-contact. As for the large air gap as well, this device can transmit electric power and a torque efficiently which compensates for exciting current in the transformer by the permanent magnet flux.

Keywords: Non-contact power supply, Permanent magnet, flywheel

DOI: 10.3233/JAE-2010-1106

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 135-144, 2010

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

Article Type: Research Article

Abstract: To simplify the calculation of the logging response, a fast approach for simulating the cylindrical electrode only with a point source is presented in this paper. This approach transforms the problem with hollow cylindrical electrodes to that with point sources, which does not only simplify the calculation, but also makes the numerical mode-matching (NMM) method can be employed directly in the calculation. The NMM method is an efficient half-numerical and half-analytical method. By using the approach …and the NMM method, a high-efficiency code has been developed and valified. The characteristics between responses and parameters are analyzed, which is crucial to the inversion problem of logging and useful for logging engineers. Show more

DOI: 10.3233/JAE-2010-1107

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 145-151, 2010

Authors: Machado, José Márcio | Shiyou, Yang | Abe, Nancy Mieko | Passaro, Angelo

Article Type: Research Article

Abstract: This work describes an optical device for the simultaneous recording of shadowgrams and schlieren images, and some results are presented concerning its applications to the study of plasma assisted flow control in airfoil models. This approach offers many advantages in comparison to other methods, specially because the use of tracer particles (like smoke in wind tunnels) is not required for the experiments, thus avoiding contaminations in the electric discharges or air flows. Besides, while schlieren images …reveal the refractive index gradients in the area of study, shadowgrams detect the second order spatial derivatives of the refractive indexes. Therefore, the simultaneous recording of these different images may give interesting information about the phenomena under study. In this paper, these images were used to confirm the existence of vortex structures in the flow induced by corona discharges on airfoil models. These structures are a possible explanation for the effects of drag reduction and lift force increasing, which have been reported in experiments of plasma assisted Aerodynamics. Show more

Keywords: Plasma assisted aerodynamics, corona discharges, air flow control

DOI: 10.3233/JAE-2010-1108

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 153-158, 2010

Authors: Dong, Longlei | Yan, Guirong | Du, Yanting

Article Type: Research Article

Abstract: A novel magnetorheological (MR) damper is presented in this paper. The check valves of the MR damper are configurated in order that the flow direction of the MR fluid is one-way, and the stretch damping force is greater than the compression damping force. The dynamic model of the damper is established, and the theoretical force-displacement diagram is consistent with the test results, which verifies that the dynamic model of the damper is applicable.

Keywords: Magnetorheological damper, structural parameters, theoretical model

DOI: 10.3233/JAE-2010-1109

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 159-165, 2010

Authors: Cundeva-Blajer, Marija | Arsov, Ljupco

Article Type: Research Article

Abstract: In the paper a thorough electromagnetic transient analysis of a combined instrument transformer will be given. A CAD procedure for transformer optimal design by using a genetic algorithm original program will be accomplished. The transient analysis will be fulfilled for the initial and optimal design as well as for a realised transformer prototype. The transient analysis will be non-linear, since the results from previous FEM-3D electromagnetic field study as well as the non-linearity of the two …transformer measurement cores will be incorporated. Show more

Keywords: Instrument transformer, finite element method, genetic algorithm

DOI: 10.3233/JAE-2010-1110

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 167-173, 2010