The alphatFilmWallFunction is boundary condition that provides a turbulent thermal diffusivity condition when using wall functions, for use with surface film models. This condition varies from the standard wall function by taking into account any mass released from the film model.


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

Boundary file

    type            patch;

Field file

    // Mandatory entries
    type            alphatFilmWallFunction;

    // Optional entries
    filmRegion      <word>;
    B               <scalar>;
    yPlusCrit       <scalar>;
    Cmu             <scalar>;
    kappa           <scalar>;
    Prt             <scalar>;

    // Inherited entries


Property Description Type Required Default
type Type name: alphatFilmWallFunction word yes -
B B coefficient scalar no 5.5
yPlusCrit y+ value for laminar -> turbulent transition scalar no 11.05
Cmu Empirical model coefficient scalar no 0.09
kappa von Karman constant scalar no 0.41
Prt Turbulent Prandtl number scalar no 0.85

The inherited entries are elaborated in:

  • fixedValueFvPatchField.H

Further information


Source code:



  • Introduced in version 2.0.0