International Journal of Applied Electromagnetics and Mechanics - Volume 31, issue 2

Authors: Rybin, Oleg | Raza, Muhammad

Article Type: Research Article

Abstract: In this paper we investigate the electric and magnetic responses from the infinite chain of infinite circular metallic cylinders periodically imbedded with dielectric matrix. The long-wavelength approximation for the complex effective dielectric and magnetic constants is obtained on base of the Effective Medium Theory. Comparisons of the analytically obtained results with the numerically calculated ones are made. Conclusions about applicability range of the proposed analytical model have been made.

Keywords: Metamaterials, effective parameters, Effective Medium Theory, electromagnetic response, microwave

DOI: 10.3233/JAE-2009-1047

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 2, pp. 61-66, 2009

Authors: Valagiannopoulos, Constantine A.

Article Type: Research Article

Abstract: Metallic wedges can be considered as parts of corner reflectors, open-ended waveguides, transmission lines and other devices with polygonal shape existing in an electromagnetics laboratory. The fields developed in the vicinity of these conducting edges possess substantial magnitudes which can affect negatively the conducted experiments and the measurement procedures. In this work, a cylindrical cap of lossy material is used to weaken the damaging radiation of the edge. The influence of the cylinder's radius, the material's …permittivity and conductivity and the angular extent of the wedge on the interfering field is illustrated through various numerical examples. Show more

Keywords: Electrical protection, metallic corner, dielectric cap, line source scattering

DOI: 10.3233/JAE-2009-1048

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 2, pp. 67-77, 2009

Authors: Qin, Zhanming | Hasanyan, Davresh | Librescu, Liviu

Article Type: Research Article

Abstract: The dynamic behavior and instability of perfectly electroconductive circular cylindrical thin shells immersed in an applied magnetic field and simultaneously carrying electric current is modeled and investigated. It is assumed that the current and the applied magnetic field are parallel and aligned to the shell's longitudinal direction. Within the framework of the technical theory of thin shells, the 2-D equations of motion that capture the interaction between the shell and the electromagnetic field are derived. Having …in view that the thin-walled structures carrying strong electric current are highly susceptible to buckling, by using the present model, the influence of the current-magnetic coupling on the shell buckling is specifically addressed. Show more

Keywords: Magnetoelasticity, flexural wave propagation, thin elastic shells, circular cylindrical shells, buckling

DOI: 10.3233/JAE-2009-1049

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 2, pp. 79-96, 2009

Authors: Jalil, Jalal M. | Al-Tae'y, Kays A.

Article Type: Research Article

Abstract: A two-dimensional thermal laminar natural convection of molten gallium in square enclosure isothermally heated and cooled from a side vertical wall was numerically computed in both time-periodic magnetic and gravity fields. The magnetic field is described by a sinusoidal time-varying equation. The thermal coefficient heat transfer has been calculated for various magnetic field strengths, but at a certain value of frequency and for different frequencies, but at a certain value of magnetic field strength. The results …show that the effect of the time-periodic magnetic field on the flow field and heat transfer is lower than that of steady (DC) magnetic field effect at the same magnetic field strength. Show more

DOI: 10.3233/JAE-2009-1050

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 2, pp. 97-111, 2009

Authors: Vendan, S. Arungalai | Manoharan, S. | Buvanashekaran, G. | Nagamani, C.

Article Type: Research Article

Abstract: In this study, Magnetically Impelled Arc Butt welding (MIAB) laboratory setup for welding carbon steel tubes of small wall thickness is designed and developed. Magnetically Impelled Arc Butt welding is an efficient two phase process which is used in highly automated factory production lines in high volume industries such as automotive manufactures. In this process, an electric arc generated between aligned and properly gapped pipes are made to rotate along the peripheral butt ends. This arc …swiftly rotates along the peripheral edges of the tubes to be welded due to the electromagnetic force resulting from the interaction of the arc current and the externally controlled magnetic field created by magnetic systems. The arc acts as a heating source providing the required heat to the butt ends of the pipes. Further an application of force on the pipe along the axial direction sets the weld. The electromagnetic force responsible for the arc rotation is governed by the magnetic flux density in the gap, the arc current and the arc length (gap size). To be precise the radial magnetic flux density is a critical factor in arc rotation and weld quality. Preliminary trials are conducted to understand the process parameters. Tubes with 45 mm Outer Diameter with 3 mm thickness are used for conducting the investigations. Further, for the first time an attempt is made to analyze the effects of weld input parameters such as welding current, welding voltage, magnetic coil voltage and magnetic coil current on the arc speed in MIAB welding process using software package STATA. The aim of this study also is to explore the distribution of the magnetic flux density in the tube gap region using finite element code ANSYS .The analysis emphasizes that the most significant factor that governs the arc speed is magnetic coil current (that creates magnetic flux density) and the welding current. Show more

Keywords: Magnetically Impelled Arc Butt (MIAB) welding, T11 tubes, lab model, magnetic coil design, STATA, finite element analysis.

DOI: 10.3233/JAE-2009-1052

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 2, pp. 113-126, 2009