The fluxCorrectedVelocity is a velocity-outlet boundary condition that for patches where the pressure is specified. The outflow velocity is obtained by zeroGradient and then corrected from the flux.


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

Boundary file

    type            patch;

Field file

    // Mandatory entries
    type            fluxCorrectedVelocity;

    // Conditional entries

        // Option-1
        volumetricFlowRate      <Function1<scalar>>;

        // Option-2
        massFlowRate            <Function1<scalar>>;

    // Optional entries
    rho             <word>;
    rhoOutlet       <scalar>;

    // Inherited entries


Property Description Type Required Default
type Type name: fluxCorrectedVelocity word yes -
volumetricFlowRate Volumetric flow rate Function1<scalar> choice -
massFlowRate Mass flow rate Function1<scalar> choice -
rho Name of density field word no rho
rhoOutlet Density initialisation value scalar no -VGREAT

The inherited entries are elaborated in:

  • fixedValueFvPatchFields.H
  • Function1.H

  • For a mass-based flux:
    • The flow rate should be provided in [kg/s].
    • If rho is none the flow rate is in [m^3/s].
    • Otherwise rho should correspond to the name of the density field
    • If the density field cannot be found in the database, the user must specify the outlet density using the rhoOutlet entry.
  • For a volumetric-based flux:
    • The flow rate is in [m^3/s].
  • rhoOutlet is required for the case of a mass flow rate, where the density field is not available at start-up.
  • The value is positive out of the domain (as an outlet).
  • May not work correctly for transonic outlets.
  • Strange behaviour with potentialFoam since the U equation is not solved.



Further information


Source code:



  • Introduced in version v1712