streamline

Description

The streamLine function object generates streamline data by sampling a set of user-specified fields along a particle track, transported by a user-specified velocity field.

Operands

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

Usage

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

streamLine1
{
    // Mandatory entries (unmodifiable)
    type            streamLine;
    libs            (fieldFunctionObjects);

    // Mandatory entries (runtime modifiable)
    U               <fieldTrack>;
    fields          (<fieldTrack> <field1> ... <fieldN>);
    setFormat       vtk;
    direction       bidirectional;
    lifeTime        10000;
    cloud           particleTracks;
    seedSampleSet
    {
        type        uniform;
        axis        x;
        start       (-0.0205 0.0001 0.00001);
        end         (-0.0205 0.0005 0.00001);
        nPoints     100;
    }

    // Optional entries (runtime modifiable)
    bounds          (0.2 -10 -10)(0.22 10 10);
    trackLength     1e-3;
    nSubCycle       1;
    interpolationScheme cellPoint;

    // Deprecated
    // trackForward true;

    // 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: streamLine	word	yes	-
libs	Library name: fieldFunctionObjects	word	yes	-
U	Name of tracking velocity field	word	yes	-
fields	Names of operand fields to sample	wordList	yes	-
setFormat	Type of output data	word	yes	-
direction	Direction to track	vector	yes	-
lifetime	Maximum number of particle tracking steps	label	yes	-
cloud	Name of cloud	word	yes	-
seedSampleSet	Name of seeding method (see below)	word	yes	-
bounds	Bounding box to trim tracks	vector	no	invertedBox
trackLength	Tracking segment length	scalar	no	VGREAT
nSubCycle	Number of tracking steps per cell	label	no	1
interpolationScheme	Interp. scheme for sample	word	no	cellPoint

Options for the seedSampleSet entry:

uniform | uniform particle seeding
cloud   | cloud of points
triSurfaceMeshPointSet | points according to a tri-surface mesh

Options for the setFormat entry:

csv
ensight
gnuplot
jplot
nastran
raw
vtk
xmgr

Options for the direction entry:

bidirectional
forward
backward

The inherited entries are elaborated in:

• functionObject

Usage by the postProcess utility is not available.

Notes on entries

• When specifying the track resolution, the trackLength or nSubCycle option should be used.

Further information

Tutorial:

• cavity

Source code:

• streamLine

API:

• Foam::functionObjects::streamLine

History: Introduced in version v1606+