Sharpening the modelling of slag entrainment during tundish pouring

This paper focuses on the numerical modelling of slag entrainment by a threephase Volume of Fluid (VOF) approach. Due to the complexity of the multi-phase flow situation and the inherently unsteady nature of the process reasonable simulations are restricted to rather coarse grids. Nevertheless, important flow structures like secondary suction vortices cannot be captured by an insufficiently resolved grid. As a consequence two numerical approaches are proposed in order to focus on local slag entrainment events within a global flow simulation. Firstly, the evolving metal-slag interface is sharpened by a solution dependent adaptive grid refinement. Secondly, possible suction vortices are tested by superimposed Chimera grids. In the latter approach a finely resolved O-shaped grid is placed around the trajectory of a representative Lagrangian fluid particle that is started from a local depression at the metal-slag interface. With help of theses sharpening approaches a global simulation of slag entrainment can be augmented by the effect of local entrainment events. Finally, the simulations are validated by corresponding water-oil experiments of a tundishstopper- mould configuration.