An Assessment of a Two Phase Calculation Procedure for Hydrodynamic Modelling of Submerged Gas Injection in Ladles

Abstract

A two phase, combined Lagrangian-Eulerian approach has been adopted to model submerged gas injection phenomena during ladle refining operations. In this, the motion of the gas phase has been computed numerically in a Lagrangian field in the form of trajectories of a steady stream of bubbles, while the liquid flow fields together with the associated level of fluid turbulence were calculated in a routine manner via the Eulerian scheme. Furthermore, to solve the Eulerian and Lagrangian field equations numerically, a sequential, iterative computational procedure, incorporating the SIMPLE procedure was applied.
The internal consistency of the two phase calculation procedures, the scope of convergence, as well as the influence of grid distribution, on predicted results have been evaluated computationally. Subsequently, model predictions on velocity and turbulence fields, particulaly within the two phase plume region of aqueous gas bubble driven systems, have been compared against corresponding experimental measurements reported in the literature. It is shown that while flow and turbulence parameters in the bulk liquid phase are predicted with reasonable accuracy, some uncertainties remain in the prediction of bubble rise velocity, turbulence kinetic energy, etc. in the two phase region, particularly in the vicinity of the gas injection nozzle and the free surface.