The SRFVelocity is a boundary condition that provides a velocity condition to be used in conjunction with the single rotating frame (SRF) model (see: SRFModel class).

Given the free stream velocity in the absolute frame, the condition applies the appropriate rotation transformation in time and space to determine the local velocity.

The optional relative flag switches the behaviour of the patch such that:

  • relative = yes: inlet velocity applied β€˜as is’:
\[\u_p = \u_{in}\]
  • relative = no : SRF velocity is subtracted from the inlet velocity:
\[\u_p = \u_{in} - \u_{p,srf}\]


Property Description
\(\u_p\) Patch velocity [m/s]
\(\u_{in}\) User-specified inlet velocity
\(\u_{p,srf}\) SRF velocity


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

Boundary file

    type            patch;

Field file

    // Mandatory entries
    type            SRFVelocity;
    inletValue      <vectorField>;
    relative        <bool>;

    // Inherited entries;


Property Description Type Required Default
type Type name: SRFVelocity word yes -
inletValue Inlet velocity vectorField yes -
relative Flag to decide if the supplied inlet value relative to the SRF bool yes -

The inherited entries are elaborated in:

  • fixedValueFvPatchField.H

Further information


Source code:



  • Introduced in version 1.5