The Mixture Model, Realizable k-ε (mm) interface (), found under the Multiphase Flow>Mixture Model>Mixture Model, Turbulent Flow branch () when adding a physics interface, is used to model the flow at high Reynolds numbers of liquids containing a dispersed phase. The dispersed phase can be bubbles, liquid droplets, or solid particles, which are assumed to always travel with their terminal velocity.

The Mixture Model, Realizable k-ε interface solves one set of Navier–Stokes equations for the momentum of the mixture. The pressure distribution is calculated from a mixture averaged continuity equation and the velocity of the dispersed phase is described by a slip model. The volume fraction of the dispersed phase is tracked by solving a transport equation for the volume fraction. Turbulence effects are modeled using the realizable two-equation k-ε model. Flow close to walls is modeled using wall functions.

Except where indicated below, the settings for this physics interface are the same as for The Mixture Model, Laminar Flow Interface and The Mixture Model, k-ε Interface.

The default Turbulence model type is RANS. A different turbulence model can be selected under Turbulence model. The default turbulence model is Realizable k-ε.

Wall treatment for the Realizable k-ε model can only be set to Wall functions. More options become available by selecting another option under Turbulence model.

Turbulence model parameters are optimized to fit as many flow types as possible, but for some special cases, better performance can be obtained by tuning the model parameters. For a description of the turbulence model and the included model parameters see Theory for the Turbulent Flow Interfaces.