International Journal of Applied Electromagnetics and Mechanics - Volume 18, issue 4

Authors: Hamid, A.-K. | Hussein, M.I.

Article Type: Research Article

Abstract: The problem of electromagnetic wave scattering by a conducting strip loaded with a lossy dielectric layer is analyzed using elliptic waves expressed in terms of complex Mathieu functions. Numerical results are obtained for the scattered field in the far zone for different axial ratios, lossy dielectric constants, and angles of incidence. The numerical results show a significant change in backscattering echo due to the presence of a lossy dielectric coating.

DOI: 10.3233/JAE-2003-287

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 18, no. 4, pp. 177-185, 2003

Authors: Okano, Yasunori | Sakai, Susumu | Yamada, Hiroshi | Hoshikawa, Keigo | Dost, Sadik

Article Type: Research Article

Abstract: A numerical simulation study was conducted for the "sessile drop method" that is one of the essential tools for conducting measurements of physical properties in droplets. The effect of the Marangoni convection on the maximum flow velocity in a hemispheric molten silicon droplet was examined. The maximum Reynolds number was correlated with the Marangoni and Biot numbers, and the surrounding temperature by Re_{max} = [-209.4{T_a(&pi;/2)/T_{mp}} + 216.8] … (BiMa) (when …BiMa < 40) and Re_{max} = [-472.5{T_a(&pi;/2)/T_{mp}} + 491.3] … (BiMa)^{2/3} (when BiMa > 40). Simulation results show that the application of a vertical magnetic field can suppress the flow in the droplet near the plate, and consequently prevent the movement of the drop, and give rise to a diffusion-limited-condition near the plate where accurate measurements of the physical properties of a melt can be made. Show more

DOI: 10.3233/JAE-2003-286

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 18, no. 4, pp. 187-197, 2003

Authors: Lin, Chun-Bo | Chen, Shin-Cheng

Article Type: Research Article

Abstract: The magnetoelastic problem of a circular shell subjected to the magnetic loadings is considered. In this paper the magnetic loadings include a point magnetic source in the domain outside or inside the circular shell or a uniform magnetic induction applied at infinity. Based upon the complex variable theory and the method of analytical continuation, the solutions of magnetic field quantities and the tangential magnetoelastic stresses in the shell and its outer and inner regions are obtained. …The tangential magnetoelastic stresses for a thin shell in air under different magnetic loadings are also provided and compared with some special case of which the solution can be found in the literature, which reveals that the present solution is exact and general. Show more

DOI: 10.3233/JAE-2003-284

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 18, no. 4, pp. 199-216, 2003

Authors: Okano, Y. | Kondo, H. | Dost, S.

Article Type: Research Article

Abstract: Transport structures such as the convective flow and temperature field patterns in a rotating metallic liquid cylinder under a static magnetic field was numerically simulated. It was found that crucible rotation suppresses the natural convection in the vertical plane while it gives rise to uniform mixing in the horizontal plane. The natural convection in the liquid is enhanced at lower magnetic field levels while it is suppressed significantly at higher magnetic field levels. It also observed …that the contribution of crucible rotation is diminished at higher magnetic field levels. Temperature distributions are not affected significantly by crucible rotation. The conclusion is that the combined effects of an applied magnetic field and a crucible rotation can be utilized to minimize undesirable radial segregations in grown crystals and obtain flatter melt/crystal interfaces in the melt crystal growth techniques such as the Vertical Gradient Freezing and Vertical Bridgman. Show more

DOI: 10.3233/JAE-2003-285

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 18, no. 4, pp. 217-226, 2003

Authors: Köksal, M. | Abbasov, T. | Herdem, S.

Article Type: Research Article

Abstract: A mathematical model is proposed for the determination of non-stationary characteristics of the cleaning process of industrial liquids in magnetic filters. The theoretical investigation which provides the determination of the variation of the captured particles both with time and along the filter matrix is based on the general filtration equations. Considering the properties of the magnetic filtration process, non-stationary filtration equations involve the capturing and detachment coefficients of the particles in the …filter matrix. The effect of the filter length on the magnetic filter performance is also presented. The obtained expressions make possible to compare the experimental and the expected theoretical results. Show more

Keywords: magnetic filters, capturing and detachment coefficients, filtration equation

DOI: 10.3233/JAE-2003-288

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 18, no. 4, pp. 227-234, 2003

Authors: Kuang, Zhen-Bang | Zhou, Zhi-Dong | Chen, Yue | Zhao, She-Xu

Article Type: Research Article

Abstract: In this paper the normalized generalized stress and strain vectors in 9-D space are introduced. A method of constructing the eigen-compliance constants and material modes for the piezoelectric material is presented, which is applied to design a new failure criterion based upon the concept of strain energy modes. In this theory, normalized generalized stress and strain vectors can be additively decomposed into nine independent and non-interaction modal components {\overline T}^{(i)} and {\overline …S}^{(i)} respectively, whose directions are called material modes, and the total strain energy is additively composed with nine independent modal energy components. Along each material mode, there is a modal energy given by {\overline T}^{(i)}{\overline S}^{(i)}/2 and it is assumed that the role of different modal energies is different in the failure event. It is postulated that the failure will occur when one of the modal energies or an appropriate linear combination of these energy modes reaches a critical value. PZT-4 piezoelectric ceramic is used as a numerical example to demonstrate the adequacy of the theory with experiment for the piezoelectric failure problem. The calculated result seems to be in good qualitative agreement with experimental data. Show more

DOI: 10.3233/JAE-2003-289

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 18, no. 4, pp. 235-250, 2003

Authors: An, Kwang-Ok | Im, Chang-Hwan | Lee, Chang-Hwan | Jung, Hyun-Kyo

Article Type: Research Article

Abstract: The new design of magnetic scale that uses magnetic levitation force is proposed. The optimal design for linearizing magnetic flux density and force is presented. The linearity of magnetic flux density and force can be improved by implementing additional metal structure on the magnet. The scale is analyzed using axis-symmetric finite element method (FEM). Global optimization is performed using evolution strategy (ES) and then more detailed shape optimization is done using sensitivity analysis. The validity of …the proposed design is verified by comparing the magnetic field quantities between conventional and proposed model. Show more

Keywords: evolution strategy (ES), finite element method (FEM), magnetic scale, optimal design, sensitivity analysis

DOI: 10.3233/JAE-2003-290

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 18, no. 4, pp. 251-258, 2003

Authors: Im, Chang-Hwan | Kim, Hong-Kyu | Jung, Hyun-Kyo

Article Type: Research Article

Abstract: In this paper, a new technique for electromagnetic topology optimization is proposed. The proposed technique is based on the large-step Markov chain (LSMC) method with novel local optimization algorithm. Because the proposed algorithm keeps a good convergence characteristic of LSMC, very fast convergence is assured. The proposed LSMC is verified by an application to an inverse reconstruction problem.

Keywords: electromagnetic topology optimization, large-step Markov chain (LSMC), inverse reconstruction problem

DOI: 10.3233/JAE-2003-291

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 18, no. 4, pp. 259-267, 2003