準正弦波磁場により誘起される非導電性流体と液体金属との界面の運動

抄録

In many electromagnetic processings of molten metals, the interfacial motion between a molten metal and a slag plays an important role on the productivity and the quality of products. However the behavior of its motion has not been precisely examined yet because of technical difficulties in the direct 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 camera. The interfacial motion caused by the imposition of a quasi-sinusoidal magnetic field is classified by use of the Shielding parameter R_ω such that a periodical oscillation and an irregular motion dominate in the low frequency range (R_ω<<1) and the high frequency range (R_ω>>1), respectively and the periodical oscillation and the irregular motion coexist around the frequency range of R_ω≈1. It is noticed that the increase in viscosity of the liquid imitating 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 the case without it.