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Description

The continuityError function object computes local, global and cumulative continuity errors for a flux field.

Local continuity error, \(\epsilon_\text{local}\):

\[\epsilon_\text{local} = \Delta_t \langle |x| \rangle\]

Global continuity error, \(\epsilon_\text{global}\):

\[\epsilon_\text{global} = \Delta_t \langle |x| \rangle\]

Cumulative continuity, \(\epsilon_\text{cum}\):

\[\epsilon_\text{cum} += \epsilon_\text{global}\]
where
\(\Delta_t\)
Time-step size
\(<.>\)
Cell-volume weighted average operator
\(x\)
\[\nabla \cdot \phi\]
\(\phi\)
Flux field

Operands

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

Usage

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

continuityError1
{
    // Mandatory entries (unmodifiable)
    type            continuityError;
    libs            (fieldFunctionObjects);

    // Optional entries (runtime modifiable)
    phi             phi;

    // 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: continuityError word yes -
libs Library name: fieldFunctionObjects word yes -
phi Name of flux field word no phi

The inherited entries are elaborated in:

Example by using the postProcess -func utility:

postProcess -func "continuityError(<field1>, <field2>, ..., <fieldN>)"

Stored properties

Reduced data

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

  • local : local continuity error
  • global : global continuity error
  • cumulative : cumulative continuity error

Further information

Tutorial:

Source code:

API:

History:

  • Introduced in version v1906