Insights into dispersed phases, such as bubbles and droplets, and multiscale interfaces in a gas-stirred ladle are of great significance to multiphase systems of metallurgical reactors, but are still challenging and not fully understood. A direct numerical simulation of dispersing phases was developed, coupling a sub-grid-scale large-eddy simulation for turbulence in fine grids with local refinement tactics. After validation with experimental data, the model was applied to investigate the bubble formation process at small length scales to understand the mechanism of bubble breakup and coalescence, to reveal the interaction of bubbles with surrounding fluid and the evolution of heterogeneous vortexes structures, to compare transient phenomena and time-averaged behavior, and to resolve the large-scale interface profile and the large number of small droplets formed by the interaction of metal, slag, and gas. The availability of results from the bubble/droplet scale using the current simulations should help advance new closure relations for the average or large-scale flows toward a multiscale model.

深入了解气泡和液滴等分散相以及气体搅拌钢包中的多尺度界面对于冶金反应器的多相系统具有重要意义，但仍然具有挑战性且尚未完全了解。开发了分散相的直接数值模拟，将细网格中湍流的亚网格尺度大涡模拟与局部细化策略相结合。经实验数据验证后，将该模型应用于小尺度气泡形成过程的研究，以了解气泡破裂和聚结的机制，揭示气泡与周围流体的相互作用和异质涡旋结构的演化，比较瞬态现象和时间平均行为，并解决大尺度界面轮廓和由金属、炉渣和气体相互作用形成的大量小液滴。使用当前模拟的气泡/液滴尺度结果的可用性应该有助于将平均或大规模流的新闭合关系推向多尺度模型。