R. I. Khalilov, A. D. Mamykin, R. S. Okatev, I. V. Kolesnichenko

THE IMPACT OF FLOW INDUCED BY ROTATING MAGNETIC FIELDS ON PROCESSES IN A MOLTEN CONDUCTIVE MEDIUM

This paper studies a method of stirring liquid metal by the action of rotating magnetic fields using two ring inductors placed next to each other. These inductors generate magnetic fields rotating in opposite directions. The aim of this study is numerical investigation of the generated fluid flow and its impact on the homogenization of a two-phase medium, as well as on the crystallization process. The impact of these electromagnetic forces proves to cause the generation of intense poloidal flow component. The arising flow is accompanied by oscillatory motion of vortex structures and their interaction resulting in effective mixing of the liquid metal. The moderate values of the force parameter have been found to lead to the most homogeneous medium under stirring. Under non-stationary action, the force parameter modulations in a certain frequency range have practically no effect on the homogeneity occurrence time and the homogeneity value. The positive effect of stirring by magnetic fields of complex topology on the rate and homogeneity of metal solidification is stated. The obtained results are relevant for improving the quality of foundry ingots.

Acknowledgments: The work was performed according to government budget plan No. 122030200191-9 and supported by grants from the RFBR and Perm Krai, project No. 20-48-596015.

References:

1. Kolesnichenko I., Pavlinov A., Golbraikh E., Frick P., Kapusta A., Mikhailovich B. The study of turbulence in MHD flow generated by rotating and traveling magnetic fields. Experiments in Fluids, 2015, vol. 56 (88). DOI: 10.1007/s00348-015-1957-z.
2. Moffatt H.K. Electromagnetic stirring. Physics of Fluids A: Fluid Dynamics, 1991, vol. 3 (5), pp. 1336–1343. DOI: 10.1063/1.858062.
3. Gelfgat Yu.M., Priede J. MHD flows in a rotating magnetic field (a review). Magnetohyrodynamics, 1995, vol. 31, Nos. 1–2, pp. 188–200.
4. Stiller J., Koal K., Nagel W., Pal J., Cramer A. Liquid metal flows driven by rotating and traveling magnetic fields. European Physical Journal: Special Topics, 2013, vol. 220, No. 1, pp. 111–122. DOI: 10.1140/epjst/e2013-01801-8.
5. Denisov S.A., Mann M.E., Khripchenko S.Y. MHD stirring of liquid metal in cilindrical mould with free surface. Magnetohydrodynamics, 1997, vol. 33, No. 3, pp. 306–314.
6. Nikrityuk P.A., Ungarish M., Eckert K., Grundmann R. Spin-up of a liquid metal flow driven by a rotating magnetic field in a finite cylinder: a numerical and an analytical study. Physics of Fluids, 2005, vol. 17 (6), pp. 067101. DOI: 10.1063/1.1897323.
7. Vogt T., Grants I., Räbiger D., Eckert S., Gerbeth G. On the formation of Taylor-Görtler vortices in RMF-driven spin-up flows. Experiments in Fluids, 2012, vol. 52, pp. 1–10. DOI: 10.1007/s00348-011-1196-x.
8. Brannover G.G., Tsynober A.B. Magnitnaya gidrodinamika neszhimayemykh sred [Magnetohydrodynamics of Incompressible Media]. Moscow, Nauka Publ., 1970, 379 с. (In Russian).
9. Frick P., Mandrykin S., Eltishchev V., Kolesnichenko I. Electro-vortex flows in a cylindrical cell under axial magnetic field. Journal of Fluid Mechanics, 2022, vol. 949, pp. A-20. DOI: 10.1017/jfm.2022.746.
10. Voller V.R., Prakash C. A fixed-grid numerical modeling methodology for convection-diffusion mushy region phase-change problems. International Journal of Heat and Mass Transfer, 1987, vol. 30, iss. 8, pp. 1709–1719. DOI: 10.1016/0017-9310(87)90317-6.
11. Brent A.D., Voller V.R., Reid K.J. Enthalpy–porosity technique for modeling convection–diffusion phase change: application to the melting of a pure metal. Numerical Heat Transfer, 1988, vol. 13 (3), pp. 297–318. DOI: 10.1080/10407788808913615.

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