The mappedFlowRate is a velocity boundary condition that describes a volumetric/mass flow normal vector boundary condition by its magnitude as an integral over its area.

The inlet mass flux is taken from the neighbour region.

The basis of the patch (volumetric or mass) is determined by the dimensions of the flux, phi. The current density is used to correct the velocity when applying the mass basis.


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

Boundary file

    type            mappedPatch;

Field file

    // Mandatory entries
    type                mappedFlowRate;

    // Optional entries
    nbrPhi              <word>;
    phi                 <word>;
    rho                 <word>;

    // Inherited entries


Property Description Type Required Default
type Type name: mappedFlowRate word yes -
nbrPhi Name of the neighbour flux setting the inlet mass flux word no phi
phi Name of the local mass flux word no phi
rho Name of the density field used to normalize the mass flux word no rho

The inherited entries are elaborated in:

Further information


Source code:



  • Introduced in version 2.1.0