| 旋转磁场下辐射加热温度对空间浮区对流的影响 |
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| 作者姓名： | 邹勇 朱桂平 李来 黄护林 |
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| 作者单位： | 1. 南京航空航天大学能源与动力学院, 南京 210016;
2. 安徽工业大学数理科学与工程学院, 安徽 马鞍山 243032 |
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| 基金项目： | 国家自然科学基金（51276089）和安徽工业大学青年基金（QZ201517）资助 |
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| 摘 要： | 采用全浮区模型数值研究旋转磁场作用下不同辐射加热温度时熔区内热毛细对流流动特性。研究发现，B0=1 mT的旋转磁场产生的洛伦兹力不足以控制熔区中的热毛细对流，熔体内流场呈现周期性旋转振荡特征，振荡频率随辐射温度的增加而减小，并与Ma数成线性关系。当Ma数较小时，温度场主要由扩散作用决定，呈二维轴对称分布；随着Ma数的增加，熔体中的温度场受对流影响，亦呈周期性振荡，且振荡主频与对流振荡主频相同。保持旋转磁场的频率不变，适当增加磁场强度，熔体内的三维振荡流将转变为准二维的旋转轴对称流，热毛细对流关于中截面镜面对称。对于Ma=21.8、32.9和43.7的熔体，分别施加2、3和5 mT的旋转磁场，熔体中的温度及速度波动被有效抑制。
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| 关 键 词： | 浮区法 热毛细对流 表面张力 数值模拟 旋转磁场 |
| 收稿时间： | 2017-05-15 |
| 修稿时间： | 2017-07-13 |
Influences of radiation temperature on convection of space floating zone under rotating magnetic field |
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| Authors: | ZOU Yong ZHU Guiping LI Lai HUANG Hulin |
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| Institution: | 1. College of Energy and Power Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
2. School of Mathematics and Physics, Anhui University of Technology, Ma'anshan 243032, Anhui, China |
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| Abstract: | Through numerical simulation on a full floating-zone, the characteristics of thermocapillary convection in the melt are studied at different radiation heating temperatures under the rotating magnetic fields (RMF). The Lorentz force induced by the applied RMF under 1mT with 50Hz is not sufficient to effectively control the thermocapillary flow. In this case, the thermocapillary flow presents a rotating oscillatory three-dimensional convection with an oscillatory frequency decreasing with radiation temperature and varying linearly with Ma number. The temperature field in the melt has a 2-D steady axisymmetric distribution which is mainly determined by the diffusion effect when the Ma number is relatively small. However, at the relatively large Ma number, the temperature of the melt is influenced by flow and exhibits periodic oscillation with the same frequency of melt convection. By fixing RMF frequency at 50Hz and increasing the magnetic field intensity, the flow in melt turns into a quasi-2D rotating axisymmetric flow from a 3D periodic oscillatory convection. Accordingly the thermocapillary convection presents a mirror-symmetry structure about the middle plane. Both the temperature and velocity fluctuation in the melts with Ma=21.8,32.9,and 43.7 are effectively suppressed under 2, 3, and 5mT RMFs, respectively. |
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| Keywords: | floating zone technique thermocapillary convection interfacial tension numerical simulation rotating magnetic field |
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