add

Description

The add function object sums a given list of (at least two or more) fields and outputs the result into a new field, where the fields possess the same sizes and dimensions:

fieldResult = field1 + field2 + ... + fieldN

Operands

Operand	Type	Location
input	{vol,surface}<Type>Field(s)	$FOAM_CASE/<time>/<inpField>s
output file	-	-
output field	{vol,surface}<Type>Field	$FOAM_CASE/<time>/<outField>

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

Usage

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

add1
{
    // Mandatory entries    (unmodifiable)
    type            add;
    libs            (fieldFunctionObjects);

    // Mandatory (inherited) entries    (runtime modifiable)
    fields          (<field1> <field2> ... <fieldN>);

    // Optional (inherited) entries
    result          <fieldResult>;
    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: add	word	yes	-
libs	Library name: fieldFunctionObjects	word	yes	-
fields	Names of the operand fields	word	yes	-

The inherited entries are elaborated in:

• functionObject
• fieldsExpression

Example by using the postProcess utility:

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

Stored properties

Fields

The add function object result field is stored on the mesh database, using the default name:

add(<field1>,<field2>,...,<fieldN>)

This can be overridden by using the result entry.

Further information

Tutorial:

• bubbleColumn
• cavity

Source code:

• API:

• Foam::functionObjects::add

History: Introduced in version v1612+