TAGAWA Toshio Institute of Advanced Material Study, Research Associate, 機能物質科学研究所, 助手 (90294983)
HIRANO Hiroyuki Okayama Science University, Lecturer, 工学部, 講師 (60264115)
KAMAKURA Katsuyoshi Toyama college of Technology, Professor, 物質工学科, 教授 (40042832)
柿本 浩一 九州大学, 機能物質科学研究所, 助教授 (90291509)
|Budget Amount *help
¥10,100,000 (Direct Cost : ¥10,100,000)
Fiscal Year 2001 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 2000 : ¥2,400,000 (Direct Cost : ¥2,400,000)
Fiscal Year 1999 : ¥4,100,000 (Direct Cost : ¥4,100,000)
Fiscal Year 1998 : ¥2,700,000 (Direct Cost : ¥2,700,000)
This is the final year of the research and research results are summarized for four years. Magnetic field is applied to the continuous steel casting process to solidify the molten steel safely. In this work, the convection of molten steel was modeled by the equation of continuity, momentum equations in the x-, y-, and z-directions and energy equation. Further more Ohm's law, conservation of electricity and Bio-Savart's law were considered.
The system is composed of a rectangular box of ?x?lx2? and O.1?lx0.1? nozzle is extended into the molten steel up to 0.5?.Molten steel is blown out through the bottom of a nozzle. Four surrounding side walls are cooled isothermally and top and bottom plane is thermally insulated. Three cases of magnetic field were considered, i. e., one coil around a rectangular enclosure, two coils at the end of x-direction and two coils at the end of y-direction. Model equations were approximated by finite difference equations and solved by a HSMAC scheme. Computational region was divided into 50^3 meshes with nonuniform staggered meshes. Numerical conditions are Re= 10^4, Re_<in> = 10^3, Gr=10^7, Pr=0.025 and Ha=0, 100, 200 and 500.
When there is no magnetic field, the jet fluid from nozzles hit the solidifying side walls and constitute four rolls. In the case of one electric coil, large roll cells were constituted at Ha = 100 and 200 but they were decreased at Ha = 500. In the case of x-directional two coils, at Ha = 100 and 200 the convection cells were similar to that at Ha = 0 but at Ha= 500, roll cells were limited to the upper part and the jet flow from nozzles did not reach the side walls. In the case of y-directional two coils, even at Ha = 500, jet flow from nozzle remained and reached to the side walls.
From these results, a coil around an enclosure appears to be best and the x-directional two coils system is the next. However, continuous steel casting process includes many factors other than this and further study is required.