Assessment of URANS-Type Turbulent Flow Modelling of a Single Port Submerged Entry Nozzle (SEN) for Thin Slab Continuous Casting (TSC) Process

The numerical methods based on the unsteady Reynolds-averaged Navier–Stokes (URANS)
equations are robust tools to model the turbulent flow for the industrial processes. They allow
an acceptable grid resolution along with reasonable calculation time. Herein, the URANS
approach is validated against a water model experiment for the special single port submerged
entry nozzle (SEN) design used in the thin slab casting (TSC) process. A 1-to-2 under-scaled
water model was constructed, including the SEN, mold, and strand Plexiglas segments.
Paddle-type sensors were instrumented to measure the submeniscus velocity supported by
videorecording of the dye injections to provide both qualitative and quantitative verification of
the SEN flow simulations. Two advanced URANS-type models (realizable k–e and shear stress
transport k–x) were applied to calculate velocity pattern on meshes with various resolutions. An
oscillating single jet flow was detected in the experiment, which the URANS simulations initially
struggled to reflect. The dimensionless analysis of the mesh properties and corresponding
adjustment of the boundary layers inside the SEN allowed to resolve the flow pattern. The
performed fast Fourier transform (FFT) verified a good numerical prediction of the flow
frequency spectrum. The corresponding simulation strategy is proposed for the industrial CC
process using the URANS approach.