Computational Fluid Dynamics Modeling of Argon–Steel (–Slag) Multiphase Flow in an Ruhrstahl–Heraeus Degasser: A Review of Past Numerical Studies

Many metallurgical functions such as dehydrogenation, decarburization, and inclusion removal are achieved during Ruhrstahl–Heraeus (RH) treatment. The realization of these functions is closely related to argon–steel–slag flow in an RH degasser. Recently, computational fluid dynamics (CFD) methods have been widely adopted to understand such multiphase flow. This review summarizes and analyzes CFD modeling of argon–steel (–slag) flow from the aspect of fundamentals of the numerical approach, focusing on CFD models and validation (homogeneous fluid model, volume of fluid–discrete phase model, and Eulerian model), bubble behaviors (deformation, expansion, coalescence, and breakup), interfacial closure laws (drag, turbulent dispersion, lift, virtual mass, and wall lubrication forces), and turbulence closures (Reynolds‐averaged approach with standard, renormalization group, and realizable k – ε models, and large eddy simulation with Smagorinsky–Lilly model). This review also suggests that future challenge is to further develop a model for coupling the dispersed interface with a wide bubble size distribution and the sharp interface with a large interfacial scale, accompanied by appropriate bubble behaviors and general closure laws of interfacial forces. As a precondition for the development of CFD models, more experiments are required to fully understand the multiphase flow in a real RH degasser.