Transient Internal Flow Characterization of a Bifurcated Submerged Entry Nozzle

Abstract

Many authors have pointed out that the steel superficial quality strongly depends on the operating conditions at the continuous caster mold. The analysis of the dynamic behavior of the fluid inside the mold Submerged Entry Nozzle (SEN) was done in this work by means of numerical simulations. In this work, the tundish sliding nozzle was not included. The results of two different turbulence models, the K-e and the Large Eddy Simulations (LES) models were compared. In simulations with both models, the velocity magnitude at 24 points inside the SEN was recorded every 0.001 s. The power spectrum of the results obtained with the LES turbulence model shows that the behavior inside the SEN is periodic. This behavior is compared with that obtained in physical simulations.KEY WORDS: continuous casting; fundamental frequencies; K-e turbulence model; LES turbulence model; submerged entry nozzle.ISIJ International, Vol. 46 (2006), No. 8, pp. 1183No. 8, pp. -1191 water model was employed. The mathematical model was solved using a commercial Computational Fluid Dynamics (CFD) software. Three different flow velocity conditions were simulated. To accomplish the dynamic analysis of the fluid inside the SEN, 24 monitoring points were defined. Several velocity magnitude time series were obtained for each monitoring point. Through a frequency analysis of the time series, it was found that jets at ports have periodic behavior which changes with SEN inlet flow velocity. Finally, it was found that the periodic frequencies obtained with mathematical simulations are similar to that measured in physical simulations. System DescriptionThe SEN geometry importance on the flow patterns inside the mold has been recognized long time ago. For instance, the SEN geometry in thin-slab continuous casting is very different to that used in the standard slab casting. 16,17) To compare the results of numerical simulations of this work with physical simulations reported in a previous work, 9) a pool-type SEN represented schematically in Fig. 1 was used. Additionally, the SEN dimensions correspond to a 1 : 1/3 scaled water model and are reported in Table 1. A bifurcated SEN with two exit ports was chosen, because this type is used commonly in actual casting and most of the numerical simulations of the fluid inside the SEN have been done using this geometry.In this work, the internal geometries of the bore and ports were assumed cylindrical. Nozzles with squared and cylindrical ports have been studied mathematically using the K-e turbulence model elsewhere. 10,12) These works have concluded that no significant differences between them were observed. The purpose of the port angle is to direct the molten steel jet into the mold cavity properly. The effect of the port angle on the flow pattern inside the mold has been widely studied. 10,12) In this work, downward ports were used. The port angle was 15 deg. This angle is commonly used at industry.Several configurations of the SEN bottom are used in actual casting. The most usual designs includes flat, pointed...

Modeling of Transient Two-Phase Flow in a Continuous Casting Mold Using Euler-Euler Large Eddy Simulation Scheme

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Turbulent Flow Phenomena and Ce2O3 Behavior during a Steel Teeming Process

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Comparison of Standard k-ε Model and RSM on Three Dimensional Turbulent Flow in the SEN of Slab Continuous Caster Controlled by Slide Gate

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