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The stability of an interface between viscous fluids subjected to a high-frequency magnetic field and consequences for electromagnetic casting

Published online by Cambridge University Press:  26 April 2006

Deepak
Affiliation:
Department of Materials Science and Mineral Engineering, University of California, Berkeley CA 94720, USA Present address: Motorola Inc., 5005 E. McDowell Road, D-304, Phoenix AZ 85008, USA.
J. W. Evans
Affiliation:
Department of Materials Science and Mineral Engineering, University of California, Berkeley CA 94720, USA

Abstract

The stability of an interface between inviscid fluids subjected to a high-frequency magnetic field has been examined previously by Garnier & Moreau (1983). The present paper extends that study to include the viscosity of both fluids in order to estimate the damping rates of the perturbations. Furthermore, Garnier & Moreau made an assumption that the frequency of oscillation of the interface could be neglected compared to the frequency of the applied field; they concluded that the applied field was not destabilizing. That (apparently reasonable) assumption has been lifted in the present work and the consequence is that the magnetic field is seen to lead to instability over a significant range of wavelengths. Application of this analysis to the electromagnetic casting of aluminium is discussed.

Type
Research Article
Copyright
© 1995 Cambridge University Press

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References

Chandrasekhar, S. 1981 Hydrodynamic and Hydromagnetic Stability, pp. 428512. Dover.
Fautrelle, Y. 1991 Free surface electromagnetic instabilities in liquid metals. In Magneto-hydrodynamics in Process Metallurgy (ed. J. Szekely, J. W. Evans, K. Blazek & N. El-Kaddah), pp. 6368. The Minerals, Metals & Materials Society.
Galpin, J. M., Gillon, P., Gelfert, Y. & Fautrelle, Y. 1990 Effects of a low frequency alternating magnetic field on a liquid metal. ISIJ Proc. Sixth Intl Iron and Steel Congress, Nagoya, pp. 362369.
Garnier, M. & Moreau, R. 1983 Effect of finite conductivity on the inviscid stability of an interface submitted to a high frequency magnetic field. J. Fluid Mech. 127, 365377.Google Scholar
Gupta, D. 1993 Electromagnetic processing: applications in ceramic composites and electromagnetic casting. PhD dissertation, University of California, Berkeley.
Hull, J. R. & Rote, D. M. 1990 Stabilization of a molten-metal/coolant-gas interface by electromagnetic fields. Phys. Fluids A 2, 443446.Google Scholar
Hull, J. R., Wiencek, T. & Rote, D. M. 1989 Magnetohydrodynamic stability in the electromagnetic levitation of horizontal molten metal sheets. Phys. Fluids A 1, 10691077.Google Scholar
McHale, E. J. & Melcher, J. R. 1982 Instability of a planar liquid layer in an alternating magnetic field. J. Fluid Mech. 114, 2740.Google Scholar
Rivat, P., Etay, J. & Garnier, M. 1991 Stabilization of a surface wave by a magnetic field. Eur. J. Mech. B/Fluids 10, 537551.Google Scholar
Sneyd, A. A. 1992 Interfacial instabilities in aluminium reduction cells. J. Fluid Mech. 236, 111126.Google Scholar
Takeuchi, S., Etay, J. & Garnier, M. 1989 Stability analysis of free surface of liquid metals levitated by electromagnetic force. ISIJ Intl, 29, 10061015.Google Scholar
Winstead, C. H. & Hoburg, J. F. 1991 Bulk-coupled electromechanical and electrothermal instability mechanisms in magnetically confined liquid metals. In Magnetohydrodynamics in Process Metallurgy (ed. J. Szekely, J. W. Evans, K. Blazek & N. El-Kaddah), pp. 4553. The Minerals, Metals & Materials Society.
Zimin, V. D. & Kolpakov, N. Yu., 1990 Magnetohydrodynamic flows and instability in the boundary of separation between the liquid metal and an electrolyte in aluminium reduction cells, 26, 345353.