Numerical study on the coalescence of multiple argon bubbles at a horizontal plane with different orifice arrangements in liquid steel under laminar flow

In the current study, the coalescence of multiple argon bubbles at a horizontal plane in liquid steel with different orifice arrangements was numerically investigated using the volume of the fluid model combined with the continuum surface force model. The numerical simulation of pairwise bubbles coalescence was verified with the experimental observation in the air-water system. The arrangements of equilateral triangle, square and rhombic orifices were considered. The effects of bubble size and orifice structure arrangement on the lateral coalescence of multiple argon bubbles were analysed. Argon bubbles coalesce into a bigger one when the initial bubble distance is less than the critical distance of bubble coalescence. The critical distance for bubble coalescence decreases with the increasing bubble size. When the orifice arrangements were arranged in square, rhombic and equilateral triangles, the coalescence of multiple bubbles become easier. In addition, the mechanisms of bubble coalescence and bounce were discussed.