Affiliations: CEA, DEN, DTCD, SCDV, LDPV, Bagnols-sur-Cèze, France
Correspondence:
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Corresponding author: Guillaume Barba Rossa, CEA, DEN, DTCD, SCDV, LDPV, BP 17171, F-30207 Bagnols-sur-Cèze, France. Tel.: +33 466 797 694; E-mail:guillaume.barbarossa@cea.fr
Abstract: In this article, we report 3D numerical simulations of
highly conductive non-magnetic particles dispersed in a moderately
conductive matrix, subject to an AC magnetic field in a range of several
hundred kHz. We address the issue of the scaling of current loops and
heating power with respect to the volume fraction of the dispersed phase.
Simulations are performed in two steps. First, a static electric potential
gradient is imposed between two opposite faces of the simulation domain and
an effective conductivity is computed in good agreement with percolation
models. Second, the particles are constrained in a spherical sub-region and
an AC magnetic field is imposed at the boundary of the domain. For small
volume fractions, the induced Joule power is in good agreement with an
analytical model of dilute dispersions. As the volume fraction increases,
wider current loops form, until the percolation threshold is reached. Then
the induced power in the spherical aggregate is well described by the power
induced in an equivalent sphere with a volume-fraction-dependent
conductivity.
