The animation shows time evolution of two bubbles coalescence. The two bubbles rising in a fluid with density ratio=1:50,viscosity ratio=1:50, Morton number=1e-5, and Eotvos number=10 are simulated.
Reference:
Inamuro, T., Ogata, T., Tajima, S. and Konishi, N., 2004, A lattice Boltzman method for incompressible two-phase flows with large density differences. J. Comput. Phys., 198, 628-644.