The effect of magnetic field on the continuous steel casting process

本文是对四年来最后一年的研究成果和研究成果的总结。将磁场应用于连铸过程中，以安全地凝固钢液。在这项工作中，钢液的对流是由连续性方程，在x-，y-和z-方向的动量方程和能量方程。在此基础上，考虑了欧姆定律、电守恒定律和Bio-Savart定律。x？lx2？O.1？lx0.1？喷嘴伸入钢水中达0.5？。钢水从喷嘴的底部吹出。四个周围的侧壁等温冷却，顶部和底部平面隔热。考虑了三种情况的磁场，即。例如，一个线圈围绕矩形外壳，两个线圈在x方向的端部，两个线圈在y方向的端部。模型方程采用有限差分方程近似，并采用HSMAC格式求解。计算区域划分为50^3个网格，网格采用非均匀交错网格。数值模拟条件为Re= 10^4，Re = <in>10^3，Gr=10^7，Pr=0.025，Ha=0，100，200和500。无磁场时，喷嘴喷出的射流冲击凝固侧壁，形成四个辊。在一个电线圈的情况下，在Ha = 100和200时构成大的滚动单元，但在Ha = 500时它们减少。在x方向双盘管的情况下，在Ha = 100和200时，对流单元与Ha = 0时的对流单元相似，但在Ha= 500时，滚动单元限于上部，并且来自喷嘴的射流没有到达侧壁。在y向双线圈的情况下，即使在Ha = 500时，喷嘴的射流仍然保持并到达侧壁。从这些结果来看，围绕外壳的线圈似乎是最好的，x向双线圈系统是次。然而，连铸过程中还包括许多其他因素，需要进一步研究。

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.