A velocity evaluation method for in-pipe metallic flow through inversion of magnetic field perturbation measured surrounding the pipe

Issue title: 26th International Workshop on Electromagnetic Nondestructive Evaluation

Guest editors: Theodoros Theodoulidis, Christophe Reboud and Christos Antonopoulos

Article type: Research Article

Authors: Chen, Rongli^a | Zheng, Xiupeng^b | Li, Xudong^a | Qiao, Liang^a | Deng, Jie^a | Chen, Hong-En^a; | Yang, Juancheng^a | Chen, Zhenmao^a;

Affiliations: [a] Shaanxi ERC of NDT and Structural Integrity Evaluation, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, China | [b] China Nuclear Power Engineering Co. Ltd, Beijing, China

Correspondence: [*] Corresponding authors: Hong-En Chen, Shaanxi ERC of NDT and Structural Integrity Evaluation, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an 710049, China. E-mail: chenhn@mail.xjtu.edu.cn. Zhenmao Chen, Shaanxi ERC of NDT and Structural Integrity Evaluation, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an 710049, China. E-mail: chenzm@mail.xjtu.edu.cn

Abstract: It is important to measure the global and/or local velocity of an in-pipe metallic flow to control its running state in applications such as a Tokamak fusion reactor. The magnetic field outside the pipe wall will be perturbed by the motion induced eddy current when the liquid metal flows across an applied static magnetic field. This phenomenon gives a possibility to evaluate the in-pipe velocity from the measured magnetic field perturbation signals. In this paper, a non-intrusive velocity evaluation method is proposed accordingly for measuring the velocity of liquid metal through measurement and inversion of the magnetic field surrounding the pipe. An efficient forward simulation method to calculate the magnetic field near a metallic flow in a static environmental magnetic field is developed at first. An inversion scheme based on the singular value decomposition and the L-curve method is then proposed to reconstruct the velocity distribution at a pipe cross-section with the linear equations correlating the flow velocity and the magnetic field regulated using the Tikhonov method. The reconstruction results of pipe flows of different velocity modes verified the feasibility and efficiency of the proposed velocity measurement method for in-pipe metallic flows.

Keywords: Liquid metal, velocity distribution, magnetic field measurement, inverse analysis

DOI: 10.3233/JAE-230149

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 4, pp. 429-439, 2024