Turbulent flow of liquid steel and argon bubbles in slide-gate tundish nozzles: Part II. Effect of operation conditions and nozzle design

A three-dimensional (3-D) finite-volume model, developed and validated in P art I of this two-part article, is employed to study steady-state two-phase turbulent flow of liquid steel and argon bubbles through slide-gate tundis h nozzles. Parametric studies are performed to investigate the effects of g as injection, slide-gate orientation, casting speed, gate opening, bubble s ize, port angle, and port shape on the flow pattern and characteristics of the jet exiting the nozzle port. Argon gas injection bends the jet angle up ward, enhances the turbulence level, and reduces the size of the backflow z one. Gas injection becomes less influential with increasing casting speed. The off-center blocking effect of the slide gate generates an asymmetric fl ow that changes with the gate orientation. The 0-deg gate orientation creat es the worst biased flow between the two ports. The 90-deg orientation gene rates significant swirl and directs the jet slightly toward one of the wide faces. The 45-deg orientation generates both types of asymmetry and, thus, appears undesirable. The horizontal jet angle indicates asymmetric flow in the horizontal plane. It increases with decreasing gate opening and decrea sing gas injection rate and ranges from 3 to 5 deg. Most jet characteristic s reach their maximum or minimum values near the critical opening of 60 pct (linear). Larger bubbles exert a greater influence on the flow pattern. Th e vertical jet angle becomes steeper with a steeper port angle and more sle nder port shape. These results will be useful for nozzle design and for fut ure modeling of flow in the mold.