2D velocity measurement using local Lorentz force velocimetry


2D velocity measurement using local Lorentz force velocimetry

Hernández, D.; Wondrak, T.; Schleichert, J.; Karcher, C.; Thess, A.

Local velocity measurement of liquid metals continues to be an unsolved issue. Contact or even contactless measurement techniques cannot be used due to the fact that metal melts, like liquid steel, are usually at high temperatures, aggressive and opaque. Fortunately, there is a contactless velocity measurement technique called Lorentz force velocimetry in which a static magnetic field is applied on the electrically conductive metal stream. This static magnetic field is produced by permanent magnets, and if their size is smaller in comparison with the cross-section of the flow, a localized magnetic field distribution on the liquid metal is achieved. As a result and according to the principles of magnetohydrodynamics, eddy currents are generated within the liquid giving rise to a localized flow-breaking Lorentz force. Additionally and owing to Newtons third law, a force of the same magnitude but in the streamwise direction acts on the permanent magnet system which is connected to an optical interference force measurement device, giving access to local velocity information. This paper presents the results of local Lorentz force velocimetry at the mini-Limmcast facility at Helmholtz-Zentrum Dresden - Rosendorf using a 10mm cubic magnet and having as test fluid Galinstan in eutectic composition. In addition, partial results of Lorentz LFV using a multi-degree-of-freedom force/torque sensor are presented.

Keywords: Lorentz force velocimetry; liquid metal; flow measurement

  • Lecture (Conference)
    3rd International Workshop on Measuring Techniques for Liquid Metal Flows (MTLM2015), 15.-17.4.2015, Dresden, Germany

Permalink: https://www.hzdr.de/publications/Publ-22928
Publ.-Id: 22928