Effect of Intense Magnetic Field on Heat Transfer between Solid-Liquid Interface

对于21世纪的创新材料来说，控制初始凝固现象是绝对必要的。然而，凝固现象已经从许多加工的角度进行了研究。在这种情况下，未来的凝固过程应该具有目前工艺中没有出现的新因素。本项目的目的是阐明强磁场施加对热传导行为的影响，以控制初始凝固。在实验中，一些熔融合金在双铜管内的通道中凝固，这也是施加电流的电极。该项目的结果如下：-通过施加高达5T的压力抑制了自然对流。-洛伦兹力可以在通道内产生循环流动，从而促进固液界面之间的换热。流体在枝晶尖端的流动受到强循环流动的扰动，强磁场对换热系数有促进作用，而磁场对流体流动有扰动抑制作用，在相同洛伦兹力的高磁场条件下，换热速率低于低磁场条件下的换热速率。

It is absolutely necessary to control initial solidification phenomena for the creation of innovative materials in 21st century. However, solidification phenomena has already investigated from many standpoint of processing. In this situation, the solidification process in the future should have the new factor which has not appeared in present processes.The purpose of this project is to clarify the effect of intense magnetic field imposition on heat transfer behavior to control initial solidification. In the experiments, some fused alloys were solidified in the channel within double copper tubes, which are also the electrodes to impose electric current. The results of this project are follows.-The natural convection was suppressed by the imposition up to 5T.-The Lorentz force can produce the circulating flow in the channel, which can promote heat transfer between solid-liquid interface. The fluid flow around the dendrite tips ware disturbed by strong circulating flows, and as the results of that, intense magnetic field can promote the heat transfer coefficient.-On the contrary, magnetic field has suppression effect of the disturbance on the fluid flow.Because of this effect, in higher magnetic field condition of the same Lorentz force, the heat transfer rate become lower that that in the lower magnetic field.