Modeling of transport of subgrid interfacial area in two-phase turbulent flows

Large-eddy simulations (LES) are the most feasible and practical approach for predictive simulations of two-phase flows. Irrespective of the choice of the numerical method for modeling the interface, interfacial processes can introduce additional scales and subgrid processes up to the molecular level. Without any subgrid model, important quantities such as interfacial area or size distributions are likely to be severely mispredicted in LES. There are two main subgrid processes to be modeled, one related to the formation of interface corrugations and the other to the transport of the dispersed phase. We recently proposed a physics-based model for the former (Hatashita et al., ILASS, 2025). In this talk, we present a new LES transport equation to model the dispersed phase in two-phase turbulent flows, which provides an alternative to the existing phenomenological models. The accuracy of the developed model will be tested against high-fidelity simulation data in different configurations.