DNS of Turbulent Primary Atomization Using a Level Set/Vortex Sheet Method

Modeling the primary atomization of turbulent liquid jets and sheets still remains an unsolved problem. Considering numerical grid resolutions typical for Large Eddy Simulations, the large scale liquid structures during primary breakup are well resolved, whereas all small scale structures are unresolved and thus require modeling. To help in the derivation of such subgrid models, DNS of the turbulent breakup of surfaces have been performed using the Level Set/Vortex Sheet method. To address the volume/mass errors inherent in the standard level set approach, a Refined Level Set Grid method is presented. LES filtering techniques consistent with the general scaling symmetries of the level set equation are discussed and applied to the DNS results. The influence of key parameters on the turbulent breakup, like the Weber number and the turbulent Weber number are explored, and a closure for the turbulent production term of the subgrid phase interface length scale is proposed. ∗Corresponding Author