A parallel Eulerian interface tracking/Lagrangian point particle multi-scale coupling procedure

This paper presents a parallel Eulerian/Lagrangian multi-scale coupling procedure for two-phase flows. At the fully resolved scale, the dynamically evolving phase interface is tracked using a Eulerian approach. In regions of the flow, where the phase interface geometry can no longer be resolved adequately, separated, small scale liquid structures are described by a Lagrangian point particle approach. The coupling procedure of these two descriptions consists of an efficient parallel algorithm that identifies tracked liquid candidate structures, removes them from the resolved Eulerian description, and inserts them into the Lagrangian description preserving their position, mass, momentum, and lower order shape. While in principle applicable to level set, Volume of Fluid, and marker particle interface tracking methods for the fully resolved scale, this paper focuses on examples from atomization simulations using the refined level set grid method.