derivedFields

Description

The derivedFields function object computes computes two predefined derived fields, i.e. rhoU, and pTotal, where the defined fields are hard-coded as follows:

$rhoU$ : $\rho \u$

$pTotal$ : $p + 0.5 \rho \mag{\u}^2$

Operands

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

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

Usage

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

derivedFields1
{
    // Mandatory entries (unmodifiable)
    type            derivedFields;
    libs            (fieldFunctionObjects);

    // Mandatory entries (runtime modifiable)
    derived         (rhoU pTotal);

    // Optional entries (runtime modifiable)
    rhoRef          1.0;

    // 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: derivedFields	word	yes	-
libs	Library name: fieldFunctionObjects	word	yes	-
derived	Names of operand fields (rhoU|pTotal)	word	yes	-
rhoRef	Reference density for incompressible flows	scalar	no	1.0

The inherited entries are elaborated in:

• functionObject

Usage by the postProcess utility is not available.

Further information

Tutorial:

• injectorPipe
• squareBend

Source code:

• derivedFields

API:

• Foam::functionObjects::derivedFields

History: Introduced in version v1906