The Phase Transport (phtr) interface (), found under the Fluid Flow > Multiphase Flow > Phase Transport branch () when adding a physics interface, is used to simulate the transport of multiple immiscible phases either in free flow or in flow through a porous medium. The interface is the same as the Phase Transport in Porous Media interface but it uses other defaults: a Phase and Transport Properties node is added by default, instead of a Phase and Porous Media Transport Properties node.

The Phase Transport interface can be used for stationary and time-dependent analyses.

The main feature is the Phase and Transport Properties node, which provides an interface for defining the phase materials along with the transporting properties.

When this physics interface is added, the following default nodes are also added in the Model Builder — Phase and Transport Properties, No Flux (the default boundary condition), and Initial Values. Then, from the Physics toolbar, add other nodes that implement, for example, boundary conditions and mass sources. You can also right-click the Phase Transport node to select physics features from the context menu.

The rest of the settings are the same as for the The Phase Transport in Porous Media Interface.

The Phase Transport and Phase Transport in Porous Media interfaces have the following domain, boundary, edge, and point nodes (listed in alphabetic order) available from the Physics ribbon toolbar (Windows users), Physics context menu (Mac or Linux users), or right-click to access the context menu (all users). For more details see the section Domain, Boundary, Edge, and Point Nodes for the Phase Transport and Phase Transport in Porous Media Interfaces.