∇

Description

The fixedNormalInletOutletVelocity is a velocity boundary condition that combines a fixed normal component obtained from the normalVelocity patch field supplied with a fixed or zero-gradiented tangential component.

The tangential component is set depending on the direction of the flow and the setting of fixTangentialInflow keyword:

  • Outflow: apply zero-gradient condition to tangential components.
  • Inflow:
    • fixTangentialInflow is true: apply value provided by the normalVelocity patch field to the tangential components,
    • fixTangentialInflow is false: apply zero-gradient condition to tangential components.

Usage

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

Boundary file 

<patchName>
{
    type            patch;
    ...
}

Field file 

<patchName>
{
    // Mandatory entries
    type                    fixedNormalInletOutletVelocity;
    fixTangentialInflow     <bool>;
    normalVelocity          <fvPatchVectorField>;

    //
    // normalVelocity
    // {
    //     type            uniformFixedValue;
    //     uniformValue    sine;
    //     uniformValueCoeffs
    //     {
    //         frequency 1;
    //         amplitude table
    //         (
    //             (0  0)
    //             (2  0.088)
    //             (8  0.088)
    //         );
    //         scale     (0 1 0);
    //         level     (0 0 0);
    //     }
    // }


    // Optional entries
    phi             <word>;

    // Inherited entries;
    ...
}

where:

Property Description Type Required Default
type Type name: fixedNormalInletOutletVelocity word yes -
phi Name of flux field word no phi
fixTangentialInflow Flag to fix the tangential component for inflow bool yes -
normalVelocity Boundary condition that provides the normal component of the velocity fvPatchVectorField yes -

The inherited entries are elaborated in:

Further information

Tutorial:

Source code:

API:

History:

  • Introduced in version 2.3.1