Interfacial motion between nonconductive fluid and liquid metal caused by a quasi-sinusoidal magnetic field

In many electromagnetic processings of molten metals, the interfacial motio n between a molten metal and a slag plays an important role on the producti vity and the quality of products. However the behavior of its motion has no t been precisely examined yet because of technical difficulties in the dire ct observation of it. Here, a new experimental method has been developed to observe the interfacial motion between a liquid metal and a non-conductive transparent liquid. In the method, a laser slit beam which was rayed into the interface from the oblique upper side is so projected on a screen as to show the shape of the interface, which is recorded by a high-speed video c amera. The interfacial motion caused by the imposition of a quasi-sinusoida l magnetic field is classified by use of the Shielding parameter R-omega su ch that a periodical oscillation and an irregular motion dominate in the lo w frequency range (R-omega much less than 1) and the high frequency range ( R-omega much greater than 1), respectively and the periodical oscillation a nd the irregular motion coexist around the frequency range of R-omega appro ximate to 1. It is noticed that the increase in viscosity of the liquid imi tating a slag acted to suppress the interfacial motion and the wave number appeared larger in the case with the liquid imitating a slag than that in t he case without it.