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Mixed elements and a two-phase free-boundary problem in magnetostatics

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Abstract

Magnetostatics consists in finding vector fields b and h such that div b = 0, rot h = j (j is given), and b = Г(h), where Г is the subgradient of a convex functional U (the magnetic coenergy). When U is the sum of a quadratic functional and of a support functional, a 2-phase free-boundary problem results, a “vector” Stefan-like problem so to speak, because the unknown is a vector-field, not a function like e.g., temperature. The special structure of the equations calls for special “mixed” finite elements. We show how they help keep at the discrete level some interesting “complementarily” properties of the problem which are present at the continuous level.

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© 1991 Springer Basel AG

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Bossavit, A. (1991). Mixed elements and a two-phase free-boundary problem in magnetostatics. In: Neittaanmäki, P. (eds) Numerical Methods for Free Boundary Problems. International Series of Numerical Mathematics / Internationale Schriftenreihe zur Numerischen Mathematik / Série Internationale d’Analyse Numérique, vol 99. Birkhäuser, Basel. https://doi.org/10.1007/978-3-0348-5715-4_7

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  • DOI: https://doi.org/10.1007/978-3-0348-5715-4_7

  • Publisher Name: Birkhäuser, Basel

  • Print ISBN: 978-3-0348-5717-8

  • Online ISBN: 978-3-0348-5715-4

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