Numerical Simulations of the Flow in Round Bloom Strands with Electromagnetic Stirring: coupled Simulation with FLUENT and EMAG

For continuous casting of steel the flow inside the liquid core is important for the quality of the end product. In-mould electromagnetic stirring (M-EMS) is a way to improve the fluid flow at the solidification front in order to achieve a good steel quality. In this paper the electromagnetic stirring of steel during continuous casting is studied by means of numerical simulations. Because of the hazardous environment during the casting process measurements are very difficult or nearly impossible to perform. Physical 1:1 scaled models of the casting process with water are available and commonly used, but because of the low electric conductivity of water these models are not applicable for cases with electromagnetic stirring. Metals which are liquid at low temperatures are very expensive and - due to the lack of transparency - measurements are again very complicated. Thus numerical simulations are nearly irreplaceable means to get detailed information of the flow field with electromagnetic stirring. The full coupling between steel flow and magnetic field is necessary, but it is strongly simplified or even neglected in other publications. Previous simulations using the FLUENT-MHD module to consider the full coupling turned out to be inefficient due to its bad convergence behaviour and due to inaccurate solutions. Thus, simulations presented in this work are performed by coupling two solvers: the electromagnetic field problem is solved with EMAG/ANSYS; the fluid flow is simulated with FLUENT. While Fluent provides the velocity- and temperature-field for EMAG, EMAG provides the averaged Lorentz-force densities and Joule losses for FLUENT.