In many applications, two-phase working fluids are considered, where the two phases refer to liquid and gas. Ansys Forte offers two types of two-phase flow simulations. In the first type, gas is modeled as a continuum, and liquid is modeled by discrete particles. In this case, the governing equations for the gas have been described in Basic Governing Equations and the models for the discrete liquid phase are described in Spray Models. In the second type of two-phase flow simulations, both gas and liquid are modeled as continuum and require Eulerian-based governing equations. Models for this type of simulation are termed as “Eulerian two-phase models” and are described in this chapter.