The uniformMixed is a mixed-type boundary condition that mix a uniform fixed value and a niform patch-normal gradient condition. The term β€œuniform” is a legacy name since the prescribed values were previously spatially uniform across that patch.


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

Boundary file

    type            patch;

Field file

    // Mandatory entries
    type                uniformMixed;

    // Optional entries
    uniformValue        <PatchFunction1<Type>>;
    uniformGradient     <PatchFunction1<Type>>;

    // Conditional entries

        // if both 'uniformValue' and 'uniformGradient' entries are set
        uniformValueFraction    <PatchFunction1<Type>>;

    // Inherited entries


Property Description Type Required Default
type Type name: uniformMixed word yes -
uniformValue Uniform fixed values PatchFunction1<Type> no -
uniformGradient Uniform gradient values PatchFunction1<Type> no -
uniformValueFraction Fraction values PatchFunction1<Type> conditional -

The inherited entries are elaborated in:

  • mixedFvPatchField.H
  • PatchFunction1.H

Further information


Source code:



  • Introduced in version v2306