volFieldValue

Description

The volFieldValue function object provides options to manipulate volume field data into derived forms, e.g. to report summations, averages and extrema.

Operations:

• none : no operation
• sum : summation
• sumMag : sum of magnitude
• average: average
• weightedAverage: weighted average
• volAverage: volume average
• weightedVolAverage: weighted volume average
• volIntegrate: volume integral
• min: minimum
• max: maximum
• CoV: coefficient of variation

Usage

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

volFieldValue1
{
    // Mandatory entries (unmodifiable)
    type            volFieldValue;
    libs            (fieldFunctionObjects);

    // Mandatory entries (runtime modifiable)
    fields          (<field1> <field2> ... <fieldN>);
    operation       <operationType>;
    regionType      <volRegion>;

    // Optional entries (runtime modifiable)
    postOperation   none;
    weightField     alpha1;

    // Optional (inherited) entries
    writeFields     false;
    scalingFactor   1.0;
    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: surfaceFieldValue	word	yes	-
libs	Library name: fieldFunctionObjects	word	yes	-
fields	Names of operand fields	wordList	yes	-
regionType	Face regionType: see below	word	yes	-
name	Name for regionType	word	yes	-
operation	Operation type: see below	word	yes	-
postOperation	Post-operation type: see below	word	no	none
weightField	Name of field to apply weighting	word	no	none

The inherited entries are elaborated in:

• fieldValue

Options for the regionType entry:

cellZone     | requires a 'name' entry to specify the cellZone
all          | all cells

Options for the operation entry:

none                 | No operation
min                  | Minimum
max                  | Maximum
sum                  | Sum
sumMag               | Sum of component magnitudes
average              | Ensemble average
volAverage           | Volume weighted average
volIntegrate         | Volume integral
CoV                  | Coefficient of variation: standard deviation/mean
weightedSum          | Weighted sum
weightedAverage      | Weighted average
weightedVolAverage   | Weighted volume average
weightedVolIntegrate | Weighted volume integral

Options for the postOperation entry:

none          | No additional operation after calculation
mag           | Component-wise `mag()` after normal operation
sqrt          | Component-wise `sqrt()` after normal operation

Usage by the postProcess utility is not available.

Stored properties

Reduced data

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

• <operation-type>(<region-name>, <field-name>) : result

Further information

Tutorial:

• twoSimpleRotors
• poolEvaporation

Source code:

• volFieldValue

API:

• Foam::functionObjects::fieldValues::volFieldValue

Related:

• surfaceFieldValue function object
• fieldValueDelta function object

History: Introduced in version 1.7.0