NUMERICAL STUDY OF STEADY TURBULENT-FLOW THROUGH BIFURCATED NOZZLES IN CONTINUOUS-CASTING

Bifurcated nozzles are used in continuous casting of molten steel, whe re they influence the quality of the cast steel slabs. The present stu dy performs two-dimensional (2-D) and three-dimensional (3-D) simulati ons of steady turbulent (K-epsilon) flow in bifurcated nozzles, using a finite-element (FIDAP) model, which has been verified previously wit h water model experiments. The effects of nozzle design and casting pr ocess operating variables on the jet characteristics exiting the nozzl e are investigated. The nozzle design parameters studied include the s hape, angle, height, width, and thickness of the ports and the bottom geometry. The process operating practices include inlet velocity profi le and angle as well as port curvature caused by erosion or inclusion buildup. Results show that the jet angle is controlled mainly by the p ort angle but is steeper with larger port area and thinner walls. The degree of swirl is increased by larger or rounder ports. The effective port area, where there is no recirculation, is increased by smaller o r curved ports. Flow asymmetry is more severe with skewed or angled in let conditions or unequal port sizes. Turbulence levels in the jet are higher with higher casting speed and smaller ports.