Numerical study of cavity dynamic and periodic features within an industrial-scale basic oxygen furnace

Basic oxygen furnace (BOF) is a key steelmaking process for yielding qualified liquid metal by removing the harmful elements sourced from the iron ore, and it features complex multiphase flow, especially the cavity, the key region strongly governing the smelting and refining. However, the understanding of the dynamic cavity characteristics, especially the periodic features within an industrial-scale BOF, remains limited. In this study, an industrial-scale BOF model is developed based on computational fluid dynamics (CFD), considering the system's multiphase nature and interactions, to quantify long-term cavity dynamics and the related periodic features. The results show that the mathematical model effectively captures the multiphase flow features inside and around the cavity. The cavity profiles, particularly, depth and radius grow significantly between 0.1 s and 0.4 s before reaching a less unsteady state. Subsequently, the cavity geometric features, including depth, radius, volume, and interfacial area, maintain distinct oscillatory behaviours over time. The time-averaged values for cavity volume, interfacial area, depth, radius, and sphericity are 0.31 m 3 , 1.95 m 2 , 0.78 m, 0.55 m, and 0.76, respectively. Furthermore, cavity depth exhibits more pronounced periodic features than other cavity properties, with the primary period being approximately 1 s for the studied scenario. This study may provide valuable insights into the further understanding and optimisation of multiphase flow behaviours within an industrial-scale BOF.