Numerical simulations of bubble formation in liquid metal

Abstract

The process of bubble formation from submerged orifices is encountered in various industrial applications. It is therefore essential to understand the dynamics of bubble formation under such conditions. In the present work, the process of bubble formation in a steel-argon system is studied using the Local Front Reconstruction Method (LFRM), a Front Tracking method that enables the simulation of interface merging and breakup. The numerical simulations are performed over a wide range of gas injection rates to study the bubble formation dynamics under quasi-static and dynamic regimes. The simulation results show that the detached bubbles in a steel-argon system are generally bigger compared to the bubbles detached in a water-air system due to higher surface tension and lower wettability. In liquid cross-flow, the bubble at the orifice mouth becomes asymmetric due to the drag force created by the liquid flow. Under non-wetting conditions, the bubble can slide over the orifice without forming a bubble neck when the orifice plate is sufficiently large. On the other hand, under wetting conditions, the detached bubble volume decreases when the orifice plate is gradually tilted from a horizontal to vertical orientation at lower shear rates. However, this trend reverses at higher shear rates because the drag force exerted by the flowing liquid becomes dominant.