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

本文的研究目的在于对液态金属自由表面电磁感应不稳定性的识别、控制和阻尼作出贡献。这种不稳定性发生在外部施加的高频磁场的影响下，这些高频磁场用于一些关键技术，如电磁悬浮熔炼和冷坩埚应用等。该项目扩展了第一作者在TU Ilmenau的DFG研究组421（FOR 421 KA 1660/2-3; FOR 421 KA 1660/1-2）之前的两项研究中所做的工作，其中实验和分析研究了这种表面不稳定性的基本机制。在这些研究中，模型配置液态金属盘和液态金属滴受到高频磁场被认为是。表面不稳定性的控制是通过外部施加定制的静磁场来管理的，已知该静磁场可以阻尼导电液体中的流体运动。该项目旨在从理论和实验上开发一种闭环控制系统，其中自由表面是控制对象，静态磁场系统用作致动器。表面不稳定性的模式识别由光学识别系统管理。然后，控制器系统产生用于驱动静磁场致动器的反馈信号。

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.