extractEulerianParticles

Description

The extractEulerianParticles function object generates particle size information from Eulerian calculations, e.g. VoF. It derives spherical particles by interrogating the Eulerian phase fraction field.

Operands

Operand	Type	Location
input	-	-
input	-	-
output file	-	-
output field 1	scalarField	$OUTPUT/d
output field 2	scalarField	$OUTPUT/soi
output field 3	labelField	$OUTPUT/tag
output field 4	vectorField	$OUTPUT/U

where $OUTPUT=$FOAM_CASE/<time>/lagrangian/eulerianParticleCloud.

Usage

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

extractEulerianParticles1
{
    // Mandatory entries (unmodifiable)
    type            extractEulerianParticles;
    libs            (fieldFunctionObjects);

    // Mandatory entries (runtime modifiable)
    faceZone        f0;
    alpha           alpha.water;

    // Optional entries (runtime modifiable)
    alphaThreshold  0.1;
    nLocations      0;
    U               U;
    rho             rho;
    phi             phi;
    minDiameter     1e-30;
    maxDiameter     1e30;

    // 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: extractEulerianParticles	word	yes	-
libs	Library name: fieldFunctionObjects	word	yes	-
faceZone	Name of faceZone used as collection surface	word	yes	-
alpha	Name of phase indicator field	word	yes	-
alphaThreshold	Threshold for alpha field	scalar	no	0.1
nLocations	Number of injection bins to generate	label	no	0
U	Name of velocity field	word	no	U
rho	Name of density field	word	no	rho
phi	Name of flux field	word	no	phi
minDiameter	Minimum diameter	scalar	no	SMALL
maxDiameter	Maximum diameter	scalar	no	GREAT

The inherited entries are elaborated in:

• functionObject
• writeFile

Usage by the postProcess utility is not available.

Notes on entries

The faceZone defines the particle collection surface, at which the phase fraction field, alpha is interpolated to identify the particle bounds.

Each isolated Eulerian region is converted into the equivalent spherical particle by default. Alternatively, the nLocations entry can be used to agglomerate the face zone to define a set of collection faces across which particle information is gathered. This can be useful to the derive particle spatial distribution. faces into a set of collection zones, for which

Stored properties

Reduced data

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

• nCollectedParticles: number of particles collected
• collectedVolume: volume of collected particles
• nDiscardedParticles: number of discarded particles
• discardedVolume: volume of discarded particles

Sample output

Further information

Tutorial:

• eulerianInjection

Source code:

• extractEulerianParticles

API:

• Foam::functionObjects::extractEulerianParticles

History: Introduced in version v1612+