軸方向に配置された固体円筒を有するパイプに磁場印加したときの液体金属流速

抄録

Macro-segregation is still an important problem to be solved. To reduce the macro-segregation, suppression of flow during solidification is essential. A magnetic field is a promising candidate because it has a function of flow suppression of en electrically conductive liquid under non-contacting operation. However, relating to the suppression of the flow induced in a solid-liquid mixed region using the magnetic field, only few studies have been done until now. Therefore, in this study, the effect of the magnetic field on the velocity of a liquid tin flowing through a flow channel with or without a solid cylinder in the flow channel made of alumina or copper has been investigated. In both the alumina and copper flow channels, the velocity decreased as the magnetic field strength increased. This result is qualitatively consistent with the theory of the Hartmann flow. The velocity in the alumina flow channel was proportional to the −0.373 power of the Hartmann number while it was proportional to the −1.86 power of the Hartmann number in a copper flow channel. The former was far away from the theory of the −1 power while the latter was close to the theory of the −2 power. This might be the difference of the entrance length under the magnetic field imposition between the alumina and the copper. The measured flow suppression effect of the magnetic field on the flow in the channel without the cylinder was larger than that with the cylinder under the same magnetic field strength.