CFD Benchmark for a Single Strand Tundish (Part I)

A Computational Fluid Dynamic (CFD) benchmark for the water model of a single‐strand continuous casting tundish was performed by ten members of the newly founded working group “Fluid Mechanics and Fluid Simulation” of the German Steel Institute VDEh. A critical comparison is drawn between laser‐optical velocity measurements and residence time measurements on the one hand and CFD simulations using different CFD programs, turbulence models, boundary conditions, proposed solutions, etc., on the other hand. The validation criteria used include, among others, the turbulence distribution, the position of the recirculation center and the maximum backflow velocity in the tundish which is induced by the recirculation, as well as the residence time distribution. The results show that the flow and turbulence structure can be computed on the basis of the Unsteady Reynolds averaged Navier‐Stokes (URANS) equations with a good degree of accuracy. The relative positional deviation of the recirculation center is ‐12.5% < Δx/L1 < 5.0%. The characteristic times Θmin, Θmax, Θ20% and Θ5% , which describe the residence time distribution, are established with a variation of ±15%. The benchmark yields important results for the sensible use of today's commonly used numerical CFD models and contributes to further improving the reliability of CFD simulations in metallurgical process engineering.