Behaviour of Molten Metal Film and Effect of Electromagnetic Force.

为了获得均匀稳定的金属液膜，利用高频磁场诱导的板形控制功能，首先利用高速录像机在水模实验中观察了狭缝喷嘴形成的液膜的下落行为。下落的液体分为两个区域。即，一个表示为出现在下落液体中部的膜流区，另一个表示为出现在膜流区两侧的槽道流区。随着下降距离的增加，气膜流区高度不断减小。在流体力学的基础上建立了预测液膜下落行为的数学模型，并通过水模型实验进行了验证，然后利用考虑磁场感应磁力增压的数学模型研究了磁场对金属液膜下落的影响。利用激光对汞表面施加的横向磁场进行了测量，并对其阻尼行为进行了测量。结果表明，对波动的抑制不依赖于场强，而取决于场强的梯度。波动的频散关系。由考虑磁场梯度的理论分析得到，并得到了实验结果的验证。利用狭缝光束测量了垂直作用于液态汞表面的直磁场和波动的衰减行为。根据磁流体力学理论，推导出了波浪运动的阻尼系数，并用实验数据验证了理论结果。利用本文导出的色散关系和阻尼系数，对完全抑制钢液波动的磁场强度进行了估算。

In order to obtain a uniform and stable molten metal film, the shape control function induced by high frequency magnetic field is utilized.Firstly, the falling behaviour of liquid film shaped by a slit nozzle was observed in a water-model experiment by use of a high speed VTR. The Falling liquid is classified into two regions. Namely, one is denoted as the film flow region appearing in the middle part of the falling liquid and the other as the channel flow region appearing in both sides of the film flow region. The eidth of the film flow region decreased continuously with increase in the falling distance. A mathematical model predicting the falling behaviour of the liquid film is developed on the basis of hydrodynamics and is verified by the water-model experimetn.Then, the effect of magnetic field on the falling molten-metal film is studied by the mathematical model taking into account the magnetic pressuer induced by magnetic field. Transverse magnetic field imposed on mercury surface mave and damping behavior was measured by making use of laser beam. It was found that the suppression of wave motion did not depend on field intensity but the gradient of it. A dispersion relation of wave motion. is derived from the theoretical analysis taking into account of the gradient of magnetic field, and is verified by the experimental results.A direct magnetic field imposed virtically to surface of liquid mercury and damping behavior of wave motion was measured by using slit beam. A damping coefficient of wave motion, is derived on the basis of magnetohydrodynamics, and experimental data verifies the theoretical results. Magnetic filed intensity to completely suppress wave motion of molten steel is evaluated by use of the dispersion relation and the damping coefficient derived here.