Numerical simulation of foaming in metal processing with population balance modeling

In this study computational fluid dynamic (CFD) model has been developed and numerical simulation has been carried out to predict the formation of foam, the number density of different bubble class, thermo-chemical reaction and multiphase flow phenomena. A new approach for the numerical simulation of foaming has been proposed and used in the present study. Numerical simulation of multiphase flow with bubble break-up and bubble coalescence model available in the open literature has also been incorporated in the CFD model. An anomaly was identified in the model of daughter bubble distribution available in the literature and rectified in the present study. Population balance modelling was used to track the number density of different bubble class. The decarburisation reaction with heat generation due to exothermic reaction was considered in the present study. The numerical prediction was based on Eulerian-Eulerian approach where the liquid phase was treated as a continuum and the gas phase (bubbles) was considered as a dispersed phase. A user subroutine was written in FORTRAN programming language to incorporate foam formation and destruction, bubble interactions and decarburisation into the main CFD software. The simulated results from the CFD models were validated against the experimental data available in the open literature.