Mathematical Simulation of Impact Cavity and Gas–Liquid Two-Phase Flow in Top–Bottom Blown Converter with Eulerian-Multifluid VOF Model

In top–bottom combined blown converter-steelmaking process, cavity shape created by oxygen jet of top lance impacting liquid metal surface and gas–liquid flow caused by bottom gas blowing play an essential role in its metallurgical efficiency. In present work, Eulerian-multifluid VOF with user‐defined functions (UDF) is adopted to study impact cavity shape and gas–liquid flow in top–bottom-blown converter, and effects of interphase force are investigated, containing drag force, turbulent dispersion force, and bubble-induced turbulence. Bubble-induced turbulence is added to the k - ε equation via UDF. The prediction ability of the optimized Eulerian-multifluid VOF is compared with that of the VOF-DPM. The simulation results of liquid velocity, impact cavity diameter, and depth are compared with experimental measurement data that are most accurately predicted with optimized Eulerian-multifluid VOF. The results show that drag force powerfully influences impact cavity shape, while turbulent dispersion force has less influence, but it dominates bottom-blowing flow direction. The stirring bath behavior can be adequately described by considering bubble-induced turbulence, and dispersed turbulence model exhibits a stronger capability than that of mixture turbulence model for prediction of liquid velocity. Top-blowing flowrate is more sensitive to the impact cavity shape than top lance height. Eulerian-multifluid VOF performs better prediction on gas–liquid two-phase flow than VOF-DPM.