Stabilization of free liquid metal surfaces influenced by high-frequency magnetic fields

• Applicant: Professor Dr.-Ing. Christian Karcher
• Subject Area: Fluid Mechanics
• Term: from 2008 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 74484053

The present proposal aims to contribute to the identification, the control, and the damping ofelectromagnetically induced instabilities of free surfaces of liquid metals. Such instabilities occur under the effects of externally applied high-frequency magnetic fields that are utilized in some metallurgic key technologies like electromagnetic levitation melting and cold crucible applications, among others. The project extends the work done in two previous studies of the first author within the DFG Research Group 421 at TU Ilmenau (FOR 421 KA 1660/2-3; FOR 421 KA 1660/1-2) where the fundamental mechanisms of such surface instabilities were investigated experimentally and analytically. As in those studies, the model configurations liquid metal disc and liquid metal drop subject to a high-frequency magnetic field are considered. The control of the surface instabilities is managed by externally applying tailored static magnetic fields that are known to damp fluid motion in electrically conducting liquids. The project aims to develop theoretically and experimentally a closed-loop control system within which the free surface is the object of control and the static magnetic field system serving as the actuator. The mode identification of surface instabilities is managed by an optical recognition system. A controller system then generates the feedback signals for the driving of the static magnetic field actuators.

• DFG Programme: Research Grants