If the Transient with Phase Initialization (

) study is being used, for the initialization to work it is crucial that there are two
Initial Values nodes and one
Initial Interface node. One of the Initial Values nodes is set to
Specify phase: Fluid 1 and the other to
Specify phase: Fluid 2. The Initial Interface node should have all interior boundaries where the interface is initially present as selection. If the selection of the Initial Interface node is empty, the initialization fails.