强磁场影响下金属相变传热的MHD效应实验研究

doi:10.7523/j.ucas.2023.021

摘要/Abstract

摘要： 通过搭建金属相变传热的综合实验系统，研究强磁场下金属镓的熔化过程，获得了磁场作用下金属镓的熔化换热特性。采用熔化过程中加热壁面与相界面的动态平均距离代替固定特征长度，以此研究熔化过程中对流换热与导热的相对强度随傅里叶数(Fo)的变化规律。结果表明：小哈特曼数(Ha)下，熔化前期具有促进熔化效果，后期则是抑制；大哈特曼数下磁场对金属镓的熔化过程中的对流具有抑制作用，熔化过程呈现层状均匀推进；磁场能够减小熔化过程中腔体底部导热主导区的高度并且抑制熔化过程中的温度波动，使熔化过程中的温度分布趋于均匀。

关键词: 均匀磁场, 相变传热, UDV测速, 液态金属

Abstract: As a highly efficient heat transport medium, the study of the melting and heat transfer characteristics of metallic fluids in phase change processes under magnetic fields is of great importance for industrial processes such as fusion reactors, electromagnetic metallurgy, and additive manufacturing. In this paper, the melting process of metallic gallium under a strong magnetic field was studied by building a comprehensive experimental system for heat transfer through phase change of metal, and the heat transfer characteristics of metallic gallium melting under the action of a magnetic field were obtained. The dynamic average distance of the heated wall from the phase interface during melting instead of the fixed characteristic length was used to study the variation of the relative strength of convective heat transfer and thermal conductivity with Fourier number (Fo) during melting. The results show that: under a small Hartmann number (Ha), the melting has a melting-promoting effect at the early stage and is inhibited at the later stage; under a large Hartmann number the magnetic field has an inhibiting effect on the convection during the melting of gallium metal, and the melting process shows a laminar and uniform advance. The magnetic field reduces the height of the dominant zone of thermal conductivity at the bottom of the cavity during the melting process and suppresses temperature fluctuations during the melting process, resulting in a uniform temperature distribution during the melting process.

Key words: uniform magnetic field, melting heat transfer, UDV, liquid metal

中图分类号:

TK124

蔡志洋, 孟旭, 张登科, 吴曦, 王增辉. 强磁场影响下金属相变传热的MHD效应实验研究[J]. 中国科学院大学学报, 2024, 41(6): 746-754.

CAI Zhiyang, MENG Xu, ZHANG Dengke, WU Xi, WANG Zenghui. Experimental study of MHD effect of phase change heat transfer in metals under the influence of a strong magnetic field[J]. Journal of University of Chinese Academy of Sciences, 2024, 41(6): 746-754.

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