Flow of steel in a one-strand slab tundish equipped with a turbulence inhibitor (TI) and a transversal gas bubbling curtain was studied using mathematical simulations, PIV measurements and Residence Time Distribution (RTD) experiments in a water model. The use of a bubbling curtain originates two recirculating flows, upstream and downstream at each of its sides. The first one meets, at some point along the tundish length and close to the bath surface, the downstream that is driven by the TI. After, free shear stresses provided by the upstream make the downstream be directed toward the tundish bottom forming a bypass flow. At the other side, in the outlet box, there is strong recirculating flow which impacts the end wall and goes directly toward the outlet. Two-phase flows simulated mathematically matched experimental flow fields measured with PIV measurements. Tundish performance for inclusions flotation is maximized when only the TI is used followed by using only the bubbling curtain. Increases of gas bubbling flow rate increase the mixing processes in the tundish according to the RTD determinations.

Sustainable oscillations of discharging jets from a two-port SEN in a thin slab caster were studied using various experimental water-modeling techniques and mathematical simulations via a combination of Reynolds Stress Model and Volume of Fluid Model to follow interface dynamics of liquid phase. A dynamic distortion of low frequency was observed on fluid flow. This distortion enhances the permanent oscillations of discharging jets and finally produces large gradients of Reynolds stresses at their boundaries with the surrounding flow. Thus high strain stresses derive into large gradients of dissipation rates of kinetic energy through the jets giving place to large and small eddies which transport energy to the free bath surface and refine the flow structure located below the tip of the SEN, respectively. As a final result non-symmetric flows with high meniscus instability are produced independently of casting speed and mold size. These results are a bottom line reference to design future SEN's for thin slab casters with improved performances.

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