turbulenceFields

Description

The turbulenceFields function object computes various turbulence-related quantities that are not typically output during calculations, including:

• k: Turbulent kinetic energy
• epsilon: Turbulent kinetic energy dissipation rate
• omega: Specific dissipation rate
• R: Reynolds stress tensor
• L: Integral-length/Mixing-length scale
• I: Turbulence intensity
• nuTilda: Modified turbulent viscosity

Additional field selections for incompressible cases:

• nut: Turbulent (edy) kinematic viscosity
• nuEff: Effective kinematic viscosity (laminar + turbulent contributions)
• devReff: Deviatoric stress tensor

Additional field selections for compressible cases:

• mut: Turbulent (eddy) dynamic viscosity
• muEff: Effective dynamic viscosity (laminar + turbulent contributions)
• alphat: Thermal eddy diffusivity
• alphaEff: Effective eddy thermal diffusivity
• devRhoReff: Deviatoric stress tensor

These fields are stored on the mesh database for further post-processing, and written as regular volume fields at write intervals.

Operands

Operand	Type	Location
input	-	-
output file	-	-
output field	vol<Type>Field	$FOAM_CASE/<time>/<outField>

where <Type>=Scalar/Vector/SphericalTensor/SymmTensor/Tensor.

Usage

Example of the turbulenceFields function object by using functions sub-dictionary in system/controlDict file:

turbulenceFields1
{
    // Mandatory entries (unmodifiable)
    type            turbulenceFields;
    libs            (fieldFunctionObjects);

    // Mandatory entries (runtime modifiable)
    // Either field or fields entries
    fields          (R devRhoReff);
    field           R;

    // Optional (inherited) entries
    region          region0;
    enabled         true;
    log             true;
    timeStart       0;
    timeEnd         1000;
    executeControl  timeStep;
    executeInterval 1;
    writeControl    timeStep;
    writeInterval   1;
}

where the entries mean:

Property	Description	Type	Required	Default
type	Type name: turbulenceFields	word	yes	-
libs	Library name: fieldFunctionObjects	word	yes	-
fields	Names of fields to store (see below)	wordList	yes	-
field	Name of a field to store (see below)	word	yes	-

The inherited entries are elaborated in:

• functionObject

Example by using the postProcess utility:

<solver> -postProcess -func turbulenceFields

Sample output

Fields stored on the mesh database with the prefix turbulenceProperties:, e.g.

turbulenceProperties:mut
turbulenceProperties:R
turbulenceProperties:devRhoReff

and written to the standard time directories according to the writeControl setting.

Further information

Tutorial:

• cavity

Source code:

• turbulenceFields

API:

• Foam::functionObjects::turbulenceFields

History: Introduced in version v1606+