A Dual-Scale Modeling Approach for Turbulent Interfaces with Finite Weber Numbers

Direct Numerical Simulation remains a prohibitively expensive task, especially for cases involving atomization. Instead of DNS, a dual-scale modeling approach (Gorokhovski and Herrmann, 2008) that describe turbulent phase interface dynamics in a Large Eddy Simulation spatial filtering context is proposed. Spatial filtering of the equations of fluid motion introduce several sub-filter terms that require modeling. Instead of developing individual closure models for the interface associated terms, 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). Advection of the phase interface on this DNS scale requires a reconstruction of the fully resolved interface velocity. In this work, results from the dual-scale LES model employing sub-filter velocity reconstruction by combined approximate deconvolution and non-linear spectral enrichment (Bassenne et al. 2019) including a sub-grid surface dynamics model (Herrmann 2013) are compared to DNS results for a phase interface in a homogeneous isotropic turbulent flow at several Weber numbers.