Several applications, such as Electromagnetic Stirring, Braking and Shaping, have been studied in order to improve the steel quality (Davidson, 1994; Idogawa et al., 1996; Negrini et al., 2000; Takeuchi et al., 1991). MHD technologies can remove, by means of electromagnetic fields, the non-metallic inclusions and the gas bubbles, which are still present in the molten steel after the refining process (Ishii et al., 1996; Takeuchi, 1995; Takeuchi et al., 1994; Thomas et al., 1994; Yoneyama et al., 1990). Even if electro-magnetic stirring (EMS) is already a commercial technology for many steel making companies, several phenomena still have to be understood in order to predict the quality of the cast (Fukuda et al., 1998; Yamamura et al., 1998).

The objective of this study is to show how the boundary layer of the molten steel in a mold for billets ð100 £ 100mm2Þ is affected by EMS. The applied magnetic field leads to an increase of the molten steel velocity gradient at the wall, causing a lift force (Saffman force), which can remove the inclusions from the solidifying shell (Fujisaki et al., 1994; Fukuda et al., 1998). The results obtained have been compared to previous ones, concerning the steel pool for a slab ð2; 000 £ 250mm2Þ: The flow pattern in the mold has been studied numerically using the finite-difference code FLUENT, which is a generalpurpose computer program for modeling fluid flow, heat transfer, and chemical reaction (Cao, 1997). It incorporates different modeling techniques and physical models for the simulation of many kinds of fluid flow problems (Fluent Inc., 1996a,b).

Eiichi Takeuchi and Takehiko Toh

Previously published in: COMPEL The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, Volume 22, Number 1, 2003  less