An a Priori Study for the Modelling of Subgrid-Scale Phenomena in the Interaction Between a Liquid Sheet and a Decaying Turbulence

Large Eddy Simulation (LES) of one-phase flow is widely used for industrial applications. However, LES of two-phase interfacial flows, i.e. two-phase flows where an interface separates liquid and gas phases, still remains a challenging task. The main issue is development of subgrid-scale models well suited for two-phase interfacial flows. Explicit filtering of 3D Direct Numerical Simulations has been employed to evaluate the order of magnitude of subgrid contributions. Two-phase interfacial flow simulations are carried out with an incompressible flow solver coupled to a ghost-fluid level-set interface capturing method. The originality of this work is the filtering of jump conditions at the interface. Subgrid terms of jump conditions are shown to derive from the filtering of both the pressure gradient term and the viscous term. Conclusions are drawn on the relative importance of the different subgrid scale contributions. These conclusions will contribute to develop subgrid-scale models which take into account the interface-turbulence coupling when LES are performed.