Sub-Filter Turbulent Velocity Reconstruction for a Volume-of-Fluid Dual-Scale approach at Turbulent Phase Interface Dynamics*

Advances to a dual-scale modeling approach are presented to describe turbulent phase interface dynamics in a LES spatial filtering context. Spatial filtering of the governing equations introduce several sub-filter terms that require modeling. Instead of developing individual closure models for the interface associated terms for LES, the dual-scale approach uses an exact closure by explicitly filtering a fully resolved realization of the phase interface. This resolved realization is maintained using a Refined Local Surface Grid approach (Herrmann, 2008) employing an unsplit geometric Volume-of-Fluid method (Owkes and Desjardins, 2014). The advection equation for the phase interface on this DNS scale requires a model for the fully resolved interface advection velocity. This velocity is the sum of the LES filtered velocity and modeled sub-filter velocity contributions. In this work, results from the dual-scale LES model using sub-filter turbulent eddy reconstruction by techniques including fractal interpolation (Scotti and Meneveau, 1999) and spectral differential filtering (Bassenne et al. 2017) are compared to DNS results for a material interface in a homogeneous isotropic turbulent flow.