The objective of the present thesis is simulation of interfacial flows using large eddy simulation and surface tension and turbulence modeling at the interface. For this purpose, surface tension models which play important role in the topology of interface was investigated and the two-dimensional stagger grid interface pressure (SGIP) model has been extended for three-dimensional cases. This model has been used to simulate three-dimensional interfacial flows and to compare the results with other existing models. Various models of surface tension force for interfacial flows, the CSF, CSS and PCIL models as well as the new proposed model, SGIP have been applied to simulate both static and dynamic cases. It is shown that the SGIP model has better accuracy than the other models. Then the application of LES in calculation of turbulent interfacial two-phase flows was investigated, in the case where each phase is resolved and interfaces remain much larger than the mesh size. In comparison with single phase flows, the application of LES to two-phase flow problems should account for the complex interaction between the interface and the turbulent motion. The derivation of the complete filtered two-phase flow governing equations has been formulated to deal with turbulence at the interface in a comprehensive and practical way. By applying the filtering operation on the traort equations of the two-phase flow, the LES traort equations are obtained. Two specific tensors and one scalar term appear due to the filtering and averaging the momentum and phase function equations. These extra terms, subgrid terms, must be modeled to close the filtered equations for two-phase flows. In the present study, two new models were presented and applied for the simulation of oil-water phase separation and turbulent jet flows. The results of the new models were compared with other studies and models indicate better performance in predicting flow treatment in comparison with other studies. Key Words: Interfacial flow; Surface tension; Turbulence modeling; Large eddy simulation; SGIP model
