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

\[\rho \u\]
\[p + 0.5 \rho \mag{\u}^2\]


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.


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

    // 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:

Usage by the postProcess utility is not available.

Further information


Source code:



  • Introduced in version v1906