Slug flow in sinusoidal channel

This is a numerical simulation of slug flow in sinusoidal channel using the finite element method and the moving-mesh/moving-boundary technique found in (https://doi.org/10.1016/j.cma.2020.112820). As can be seen 3 confined drops are flowing thru the corrugated channel and its cross-sectional variation changes the drops shapes periodically. The center drop is pushed forward and coalescence with the front drop may occurs.