Perturbation of eddy-currents by one inclusion in liquid metal

Rafaël Guichou (1) , Hervé Ayroles (1) , Rémi Zamansky (1) , Wladimir Bergez (1) , Philippe Tordjeman (1) , Kevin Paumel (2)

1 IMFT - Institut de mécanique des fluides de Toulouse
2 CEA - Commissariat à l'énergie atomique et aux énergies alternatives

In this article, we present an analytical model to calculate the perturbation of the magnetic vector potential due to a non-conducting inclusion in a liquid metal translated at constant velocity. The model is valid for a low magnetic Reynolds number, Rem, and a low shielding parameter, Sω. We establish that the first order perturbation of the vector potential can be directly obtained from the value of the unperturbed eddy-current calculated at the location of the inclusion. An ECFM (Eddy-Current FlowMeter) device has been designed to validate the model and to study the frequency effects of the eddy-current and the volume of one inclusion and its location. We observe a good agreement between the model predictions and experimental data within the limit of the validity of the model. Based on scaling analysis, we show that a unique relation exists between the perturbation of the emf (electromotive force) measured with the ECFM and the volume of the inclusion and its location, which reflects the self-similarity of the model solution.

Mots clés: Magnetic vector potential; MHD; Eddy-current; Scaling analysis

Domaines: Mécanique des fluides [physics.class-ph]

Rafaël Guichou, Hervé Ayroles, Rémi Zamansky, Wladimir Bergez, Philippe Tordjeman, et al.. Perturbation of eddy-currents by one inclusion in liquid metal. Journal of Applied Physics, 2019, 125 (9), pp.1-6. ⟨10.1063/1.5055062⟩. ⟨hal-02134624⟩