The Influence of Eddy Effect of Coils on Flow and Temperature Fields of Molten Droplet in Electromagnetic Levitation Device
The Influence of Eddy Effect of Coils on Flow and Temperature Fields of Molten Droplet in Electromagnetic Levitation Device
复制标题
电磁悬浮装置中线圈涡流效应对熔滴流场和温度场的影响
DOI：
10.1007/s11663-015-0360-8
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发表时间：
2015-08-01
影响因子：
3
通讯作者：
Shi, Wan-Yuan
中科院分区：
文献类型：
--
作者：
Feng, Lin;Shi, Wan-Yuan
在这项工作中，通过一系列轴对称数值模拟研究了线圈的涡流效应对电磁悬浮熔滴中的磁场、流动和温度场的影响。在电磁悬浮装置中，金属液滴和线圈都是导电材料，因此由于涡流效应，它们中的电流密度分布应该是不均匀的。然而，在以前的工作中，仅考虑金属熔滴中的涡流效应，而通常忽略线圈中的涡流效应。由于线圈与金属熔滴的距离一般为几毫米，线圈中电流密度的不均匀分布实际上对磁场、流场和温度场的计算产生重要影响。在这里，我们同时考虑金属熔滴和线圈中的涡流效应。以半径为4mm的熔融铜滴为典型例子，在此条件下进行了升力、吸收功率、流体流动和温度场的仔细计算和分析。结果表明，与忽略涡流效应时相比，涡流效应导致悬浮和熔化过程中的磁力、速度和温度更高。更重要的是，随着液滴和线圈的距离越近，这种影响越大，这与实验测量相符。因此，我们建议在本课题的数值模拟中考虑线圈的涡流效应，以获得更可靠的结果。
In this work, the influence of eddy effect of coils on magnetic, flow, and temperature fields in an electromagnetically levitated molten droplet was investigated by a serial of axisymmetric numerical simulations. In an electromagnetic levitation device, both metal droplet and coils are conductive materials, therefore the distributions of current density in them should be non-uniform as a result of the eddy effect. However, in previous works, the eddy effect was considered alone in metal droplet but ignored in coils usually. As the distance of coils and metal droplet is several millimetres in general, the non-uniform distribution of current density in coils actually gives important influences on calculations of magnetic, flow, and temperature fields. Here, we consider the eddy effect both in metal droplet as well as that in coils simultaneously. Lifting force, absorbed power, fluid flow, and temperature field inside a 4-mm radius molten copper droplet as a typical example are then calculated and analyzed carefully under such condition. The results show that eddy effect leads to higher magnetic force, velocity, and temperature in both levitating and melting processes than those when the eddy effect is ignored. What is more, such influence increases as the distance of droplet and coils becomes closer, which corresponds to experimental measurement. Therefore, we suggest that eddy effect of coils should be considered in numerical simulation on this topic to obtain more reliable result.