Identification of magnetic deposits in 2-D axisymmetric eddy current models via shape optimization

Zixian Jiang (1) , Houssem Haddar (1) , Armin Lechleiter (2) , Mabrouka El-Guedri (3)

1 DeFI - Shape reconstruction and identification
2 ZeTeM - Zentrum für Technomathematik - Universität Bremen
3 EDF R&D STEP - Simulation et Traitement de l'information pour l'Exploitation des systèmes de Production

The non-destructive control of steam generators is an essential task for the safe and failure-free operation of nuclear power plants. Due to magnetite particles in the cooling water of the plants, a frequent source for failures are magnetic deposits in the cooling loop of steam generators. From eddy current signals measured inside a U-tube in the steam generator, we propose and analyze a regularized shape optimization algorithm to identify magnetic deposits outside the U-tube with either known or unknown physical properties. Motivated by the cylindrical geometry of the U-tubes we assume an axisymmetric problem setting, reducing Maxwell's equations to a 2-D elliptic eddy current problem. The feasibility of the proposed algorithms is illustrated via numerical examples demonstrating in particular the stability of the method with respect to noise.

Domaines: Analyse numérique [math.NA]; Equations aux dérivées partielles [math.AP]; Physique mathématique [math-ph]; Analyse numérique [cs.NA]

Zixian Jiang, Houssem Haddar, Armin Lechleiter, Mabrouka El-Guedri. Identification of magnetic deposits in 2-D axisymmetric eddy current models via shape optimization. Inverse Problems in Science and Engineering, 2015. ⟨hal-01220230⟩