Field gradient analysis of a conical helix [for EM levitation melting]

Author

Bayazitoglu, Yildiz ; Sathuvalli, Udaya B.

Author_Institution

Dept. of Mech. Eng., Rice Univ., Houston, TX, USA

Volume

29

Issue

1

fYear

1993

fDate

1/1/1993 12:00:00 AM

Firstpage

88

Lastpage

97

Abstract

The excitation coil used in electromagnetic-levitation melting consists of a few turns of copper tubing wound over a length of a few centimeters. The behavior of the field and the Lorentz force on a conducting specimen in it are studied for a typical coil. The equations for the field and field gradient for this excitation coil are obtained by modeling it as a helix wound over the surface of a cone. Results for the field and the Lorentz force on a conducting specimen due to current flowing in a right circular helix are presented. These results are compared with the results for an equivalent stack of coaxial loops for a typical laboratory coil. It is shown that the helix model is more realistic than the `stack of coaxial loops´ model. In the limit of vanishing pitch of the coil, the helix and the stack models are shown to be equivalent

Keywords

coils; eddy currents; magnetic fields; magnetic levitation; melting; Lorentz force; coaxial loops; conducting specimen; conical helix; electromagnetic-levitation melting; equivalent stack; excitation coil; field gradient analysis; induced eddy currents; limit of vanishing pitch; right circular helix; Coaxial components; Coils; Conductors; Eddy currents; Lorentz covariance; Magnetic analysis; Magnetic fields; Magnetic levitation; Stability; Wounds;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.195552

Filename

195552