The valueAverage function object computes the ensemble- or time-based singular-value average values, with optional windowing, from the output of function objects that generate non-field type values, e.g. Cd of forceCoeffs or momentum_x in momentum function objects.


Operand Type Location
input - -
output file dat $FOAM_CASE/postProcessing/<FO>/<time>/<file>
output field - -


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

    // Mandatory entries (unmodifiable)
    type              valueAverage;
    libs              (fieldFunctionObjects);

    // Mandatory entries (runtime modifiable)
    functionObject    <FO>;                       // forceCoeffs1;
    fields            (<field1> ... <fieldN>);    // (Cm Cd Cl);

    // Optional entries (runtime modifiable)
    resetOnRestart    false;
    window            0.5;

    // Optional (inherited) entries
    writePrecision    8;
    writeToFile       true;
    useUserTime       true;
    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: valueAverage word yes -
libs Library name: fieldFunctionObjects word yes -
functionObject Name of function object to retrieve data word yes -
fields Names of operand fields wordList yes -
resetOnRestart Reset the averaging on restart bool no false
window Averaging window scalar no VGREAT

The inherited entries are elaborated in:

Usage by the postProcess utility is not available.

Sample output

Text reporting:

  • Average value, e.g. using drag coefficient, Cd, retrieved from a forceCoeffs function object:

    CdMean: 0.3

Stored properties

Reduced data

The following data are stored by the function object, and can be used by other function objects:

  • <field-name>Mean : average value

Further information


Source code: