The outletPhaseMeanVelocity is a velocity-outlet boundary condition that adjusts the velocity for the given phase to achieve the specified mean thus causing the phase-fraction to adjust according to the mass flow rate.

Typical usage is as the outlet condition for a towing-tank ship simulation to maintain the outlet water level at the level as the inlet.


The condition requires entries in both the boundary and field files.

Boundary file

    type            patch;

Field file

    // Mandatory entries
    type            outletPhaseMeanVelocity;
    Umean           <scalar>;
    alpha           <word>;

    // Inherited entries


Property Description Type Required Default
type Type name: outletPhaseMeanVelocity word yes -
Umean Mean velocity normal to the boundary scalar yes -
rho Name of phase-fraction field word yes -

The inherited entries are elaborated in:

Further information


Source code:



  • Introduced in version 2.3.0