Numerical and experimental investigation of the contactless inductive flow tomography in the presence of strong static magnetic fields

M. Ratajczak - T. Wondrak - F. Stefani - S. Eckert

Helmholtz-Zentrum Dresden-Rossendorf e.V., P.O. Box 510119, 01314 Dresden, Germany

Abstract
In the continuous casting industry, electromagnetic brakes (EMBr) are used to influence the mould flow, although their effect on the flow cannot be directly examined due to a lack of market-ready measurement techniques for liquid metal flows. Contactless inductive flow tomography (CIFT) is a technique that is able to reconstruct the mean flow structure of an electrically conducting melt by measuring the flow-induced perturbations of an applied magnetic field outside the melt and solving the linear inverse problem. Since CIFT relies on the measurement of magnetic fields, the question arises: Does CIFT work in the presence of a strong static magnetic field like that of an EMBr that superimposes and distorts the applied excitation magnetic field? In this paper, we will examine the effects of EMBr on CIFT with simulations and accompanying measurements. Tables 1, Figs 8, Refs 15.