A dual scale volume-of-fluid approach for modeling turbulent phase interface dynamics

In this report, a dual-scale modeling approach is presented to describe turbulent twophase interface dynamics in a Large Eddy Simulation spatial filtering context. To close the unclosed terms related to the phase interface arising from filtering the Navier-Stokes equation, a resolved realization of the phase interface is explicitly filtered. This resolved realization is maintained on a high resolution over-set mesh using a Refined Local Surface Grid approach employing an un-split, geometric, bounded, and conservative Volume of Fluid method. While the required model for the resolved realization of the interface advection velocity includes the effects of sub-filter surface tension, sub-filter shear, and turbulent eddies, the focus in this report will be on advection by sub-filter turbulent eddies. Examples of a two-dimensional Rayleigh-Taylor instability and the motion of an interface in homogeneous isotropic turbulence are presented.