  Droplet(s) breakup and coalescence have been simulated by the finite
volume/moving mesh interface tracking method (MMIT) with adaptive mesh refining
and coarsening. In this method, the interface is zero-thickness and moves in a
Lagrangian fashion. The breakup and the coalescence of the interfaces are
simulated by the mesh separation and mesh combination schemes. Three cases are
displayed in this video, which include the relaxation and breakup of an
initially extended droplet, two identical droplets off-center collision, and a
droplet pair in a shear flow. The mesh adaptation is capable of capturing large
deformations and thin regions, and the smallest length resolved is three orders
of magnitude smaller than the droplet radius. The fluid dynamics videos of the
simulations are to be presented in the Gallery of Fluid Motion, 2010.
