Subgrid-scale Modeling of Liquid Sheet Fragmentation*

In this talk, we present a method for the prediction of the drop-size distribution from the aerodynamic breakup of a liquid sheet whose interface is maintained below the mesh size. A two-plane interface reconstruction is used within an Eulerian volume of fluid solver to capture the subgrid-scale sheet interface, while an algorithm based on connected component labeling is used to identify thin fluid regions that should undergo breakup. A sheet breakup model is then applied to the identified fluid regions to convert the associated Eulerian volume representation into droplets represented as Lagrangian point particles. The method is validated using canonical simulations of a perturbed sheet in a periodic domain and of a spherical drop. We investigate the ability of the method to predict the behavior of the spherical drop at different breakup regimes characterized by the non-dimensional Weber number with comparisons to experimental drop-size distributions. We also perform mesh-refinement studies to determine the meshsize-dependence of the method which then informs the computational cost of the implementation of the proposed method in full-scale atomization simulations.