Numerical Simulation of Two-phase Flow in a Slab Mold by MUSIG Model

An Euler-Euler approach has been employed to investigate the effects of varying flow rate of argon gas and static magnetic field on the flow pattern in a slab mold. The mathematical model is based on the k − ǫ turbulence model and coupled with the MHD model in CFX. In this work, three dimensional localized DC magnetic fields were constructed and calculated by a finite element method and then imported into CFX. The results show that a static magnetic field does not always slow down the bulk flow, but occasionally gives rise to large eddies for increasing magnetic field strengths. In principle, the injection of Argon gas is able to suppress the fluctuation of the free surface and to reduce the penetration depth significantly. However, gas bubbles may produce a reversed flow surrounding the nozzle at the meniscus if large bubbles float up rapidly in the case the flow rate ratio of argon gas to molten steel reaches a certain value. The MUSIG (multiple size group) model considering coalescence and breakup of bubbles provides an effective tool to solve the multiphase flow and to get insight into the flow pattern in a continuous casting mold with argon gas injection.