A DNS database to improve atomization modeling

Recent advances in interface tracking method allows us to use them as a tool to study primary atomization. Some recent works have performed accurate Direct Numerical Simulation of turbulent liquid jets which are very promising. Unfortunately, these simulations have shown that, even with a high resolved DNS of 6 billions points [1], the finest scales of the flow are not resolved. This issue shows that subgrid models are necessary to modelize the physics under this particular scale. In order to improve modeling, it is useful to study simpler configurations which allows us to solve all relevant scales of the flow. In single-phase flows, DNS of Homogeneous I sotropic Turbulence (HIT) is still used to study scalar mixing and the Kolmogorov theory. Extension of this configuration to two-phase flows to characterize important processes (for example turbulence/interface inte ractions, vaporization) is emerging in recent DNS studies. The aim of this work is to pursue these studies by analyzing the interface behaviour of two-phase flows in a forced HIT. This analysis is performed over a large range of liquid volume fractions. From these results we can extract useful informations in order to improve modeling of primary atomization. Both phase are resolved in DNS, the interface tracking method used is a coupled Level Set/VOF method. High density ratio between the two phases is chosen to simulate realistic engine conditions. Quantitative and qualitative aspects are analyzed, with a main focus on interfacial quantities (equilibrium interface density and Weber number), which are key parameters for primary atomization modeling.