Description🔗
The zeroGradient
function object creates a volume field with zero-gradient
boundary conditions from another volume field.
The result can be used, for example, to post-process near-wall field values.
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 zeroGradient
function object by using functions
sub-dictionary in system/controlDict
file:
zeroGradient1
{
// Mandatory entries (unmodifiable)
type zeroGradient;
libs (fieldFunctionObjects);
// Mandatory entries (runtime modifiable)
fields (<field1> ... <fieldN>); \\(U "(T|k|epsilon|omega)");
// Optional entries (runtime modifiable)
result @@<name>;
// 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: zeroGradient | word | yes | - |
libs | Library name: fieldFunctionObjects | word | yes | - |
fields | Name of the operand fields | wordList | yes | - |
result | Name of the output field | word | no | zeroGradient(@@) |
The inherited entries are elaborated in:
Usage by the postProcess
utility is not available.
Notes on entries🔗
A list of fields can contain exact names or regular expressions. The token ‘\@\@’ in the result name is replaced by the name of the source field. In the special case of a single source field (specified as a non-regex), the ‘\@\@’ token checking is suppressed.
The function object will skip over fields that would not benefit e.g.
processor
, empty
, zeroGradient
, symmetry
patches.
This check should also prevent processing fields multiple times.
Further information🔗
Tutorial:
Source code:
API:
History:
- Introduced in version v1612+