randomise

Description

The randomise function object adds a random component to an input field, with a specified perturbation magnitude.

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 randomise function object by using functions sub-dictionary in system/controlDict file:

randomise1
{
    // Mandatory entries (unmodifiable)
    type            randomise;
    libs            (fieldFunctionObjects);

    // Mandatory entries (runtime modifiable)
    magPerturbation 0.1;

    // Mandatory (inherited) entries (runtime modifiable)
    field           <inpField>;

    // 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: randomise	word	yes	-
libs	Library name: fieldFunctionObjects	word	yes	-
magPerturbation	The magnitude of the perturbation	scalar	yes	-
field	Name of the operand field	word	yes	-

The inherited entries are elaborated in:

• functionObject
• fieldExpression

Example by using the postProcess utility:

postProcess -func "randomise(<field>)"

Further information

Tutorial:

• cavity
• splashPanel

Source code:

• randomise

API:

• Foam::functionObjects::randomise

History: Introduced in version v1606+