Additional Information on “Fluid Flow Characterization in Asymmetric Tundish” by Cui, Liu and Li

• Published in: ISIJ International 2018/10/15, Vol.58(10), pp.1953-1955
• Main Authors: Braga, Bernardo Martins, Tavares, Roberto Parreiras
• Format: Article
• Language: English
• Subjects: asymmetric tundish; mathematical simulation; multi-strand tundish; residence time distribution; water model
• ISSN: 0915-1559; 1347-5460
• DOI: 10.2355/isijinternational.ISIJINT-2018-368

Cui et al.1) proposed a methodology for the fluid flow characterization of asymmetric tundishes that does not rely on any idealized flow model. First, the E curves of each tundish strand is obtained through the pulse input experiment. Subsequently, the E curves are converted into F curves by integration. Then, the dead volume fraction of the entire tundish (Vd /V) is calculated so as to evaluate the overall tundish performance. Finally, the flow uniformity among tundish strands is assessed through quantities obtained from the strand F curves (i.e. maximum difference between strand F curves for two-strand tundishes or maximum standard deviation among strand F curves for multi-strand tundishes). In the present work, the calculation procedure for the methodology of Cui et al.1) is discussed in detail. It was identified a problem in the obtention of F curve by Cui et al.1) that modified the actual formulas of Vd /V. In addition, this work presents new equations that facilitate the calculation of Vd /V when physical and mathematical models are employed. Moreover, the most convenient definition of the dead volume fraction is studied. It was found that Vd /V can distinguish different flows more effectively if it is based on one dimensionless residence time rather than two. Furthermore, some parameters for assessing the flow uniformity among tundish strands were compared. The area metric described by Oberkampf and Roy11) is the recommended one.