Improving primary atomization modeling through DNS of two-phase flows

•Recent progresses allow for a direct resolution of both flow and interface.•Direct resolution is applied to study atomization and interface deformation.•Statistics of the interface density (quantity of liquid surface) is extract from DNS.•These statistics are used as a reference to evaluate the model performance in dense two phase flows.•A correction to the model is proposed, showing good agreement with DNS data. This study employs DNS of two-phase flows to compare and improve primary atomization models used in RANS and/or LES formalisms. The paper is based on the ELSA model, which was initially proposed in Vallet and Borghi [Vallet, A., Borghi, R., 1999. Modélisation eulerienne de l’atomisation d’un jet liquide. Comptes Rendus de l’Académie des Sciences – Series IIB – Mechanics–Physics–Astronomy 327(10), 1015–1020]. This model has been used successfully in many studies to describe the complete liquid atomization process from primary atomization to the dispersed spray. A two-phase flow homogeneous isotropic turbulence was used for the numerical configuration. A statistical analysis of the equilibrium Weber number was performed with a DNS of two-phase flows to verify the definition given by the ELSA model. This verification was carried out for various liquid volume fractions, mesh resolutions, and surface tensions. An ensemble averaging of the time evolution of the interface density was performed to check the validity of the interface density equation used in the ELSA model. Proposed improvements of the ELSA model were compared with the reference DNS for multiple configurations. The new proposal shows good agreement with the DNS.