? ? ? The bubble transportation and bubble-steel-slag interactions in gas-stirring vessels is a quite complicated multiphase flow, intricate with multiple time and space scales. The present work implements a two-way discrete-continuum transition algorithm in a multiscale model for the simulation of bubble injection, coalescence, and its interaction with the bath and slag layer. The interfaces between liquid steel, gas, and slag are captured using the volume of fluid (VOF) and adaptive mesh refinement (AMR) methods for adaptively improving the interface resolution. For microbubbles that are unable to be resolved, a discrete phase model (DPM) is applied by considering the coalescence using a modified collision model. Most importantly, the two-way transition between DPM and VOF-AMR is mainly achieved by introducing criteria and specific source terms into the equations. The predicted bubble diameter evolution and the slag eye size in the vessel are both in good agreement with the experimental measurements. Using the present modeling framework, the bubbling flow and the slag layer behavior are both well represented, including the detailed phenomena of bubble aggregation and breakage, bubble splashing on the top surface, slag eye fluctuation, and slag droplet formation, etc.

? ? ? The work is done in April, 2022, and the paper is now published in:

? ? ? https://link.springer.com/article/10.1007/s11837-022-05675-5

The following animations belong to this publication:

The discrete-to-continuous?transition:

The continuous-to-discrete transition:

The top surface splashing: