The standard set of Lagrangian clouds are now selectable at run-time.
This means that a solver that supports Lagrangian modelling can now use
any type of cloud (with some restrictions). Previously, solvers were
hard-coded to use specific cloud modelling. In addition, a cloud-list
structure has been added so that solvers may select multiple clouds,
rather than just one.
The new system is controlled as follows:
- If only a single cloud is required, then the settings for the
Lagrangian modelling should be placed in a constant/cloudProperties
file.
- If multiple clouds are required, then a constant/clouds file should be
created containing a list of cloud names defined by the user. Each
named cloud then reads settings from a corresponding
constant/<cloudName>Properties file. Clouds are evolved sequentially
in the order in which they are listed in the constant/clouds file.
- If no clouds are required, then the constant/cloudProperties file and
constant/clouds file should be omitted.
The constant/cloudProperties or constant/<cloudName>Properties files are
the same as previous cloud properties files; e.g.,
constant/kinematicCloudProperties or constant/reactingCloud1Properties,
except that they now also require an additional top-level "type" entry
to select which type of cloud is to be used. The available options for
this entry are:
type cloud; // A basic cloud of solid
// particles. Includes forces,
// patch interaction, injection,
// dispersion and stochastic
// collisions. Same as the cloud
// previously used by
// rhoParticleFoam
// (uncoupledKinematicParticleFoam)
type collidingCloud; // As "cloud" but with resolved
// collision modelling. Same as the
// cloud previously used by DPMFoam
// and particleFoam
// (icoUncoupledKinematicParticleFoam)
type MPPICCloud; // As "cloud" but with MPPIC
// collision modelling. Same as the
// cloud previously used by
// MPPICFoam.
type thermoCloud; // As "cloud" but with
// thermodynamic modelling and heat
// transfer with the carrier phase.
// Same as the limestone cloud
// previously used by
// coalChemistryFoam.
type reactingCloud; // As "thermoCloud" but with phase
// change and mass transfer
// coupling with the carrier
// phase. Same as the cloud
// previously used in fireFoam.
type reactingMultiphaseCloud; // As "reactingCloud" but with
// particles that contain multiple
// phases. Same as the clouds
// previously used in
// reactingParcelFoam and
// simpleReactingParcelFoam and the
// coal cloud used in
// coalChemistryFoam.
type sprayCloud; // As "reactingCloud" but with
// additional spray-specific
// collision and breakup modelling.
// Same as the cloud previously
// used in sprayFoam and
// engineFoam.
The first three clouds are not thermally coupled, so are available in
all Lagrangian solvers. The last four are thermally coupled and require
access to the carrier thermodynamic model, so are only available in
compressible Lagrangian solvers.
This change has reduced the number of solvers necessary to provide the
same functionality; solvers that previously differed only in their
Lagrangian modelling can now be combined. The Lagrangian solvers have
therefore been consolidated with consistent naming as follows.
denseParticleFoam: Replaces DPMFoam and MPPICFoam
reactingParticleFoam: Replaces sprayFoam and coalChemistryFoam
simpleReactingParticleFoam: Replaces simpleReactingParcelFoam
buoyantReactingParticleFoam: Replaces reactingParcelFoam
fireFoam and engineFoam remain, although fireFoam is likely to be merged
into buoyantReactingParticleFoam in the future once the additional
functionality it provides is generalised.
Some additional minor functionality has also been added to certain
solvers:
- denseParticleFoam has a "cloudForceSplit" control which can be set in
system/fvOptions.PIMPLE. This provides three methods for handling the
cloud momentum coupling, each of which have different trade-off-s
regarding numerical artefacts in the velocity field. See
denseParticleFoam.C for more information, and also bug report #3385.
- reactingParticleFoam and buoyantReactingParticleFoam now support
moving mesh in order to permit sharing parts of their implementation
with engineFoam.
Description
Stops the run when the specified clock time in second has been reached
and optionally write results before stopping.
The following actions are supported:
- noWriteNow
- writeNow
- nextWrite (default)
Examples of function object specification:
\verbatim
stop
{
type stopAtClockTime;
libs ("libutilityFunctionObjects.so");
stopTime 10;
action writeNow;
}
\endverbatim
will stop the run at the next write after the file "stop" is created in the
case directory.
Usage
\table
Property | Description | Required | Default value
type | type name: stopAtClockTime | yes |
stopTime | Maximum elapsed time [s] | yes |
action | Action executed | no | nextWrite
\endtable
By default the case stops following the next write but stopping immediately with
or without writing are also options.
The stopAtFile functionObject derived from stopAt stops the run when a file
predefined file is created in the case directory:
Description
Stops the run when the specified file is created in the case directory.
The default name of the trigger file is \c $FOAM_CASE/<name> where \c
<name> is the name of the functionObject entry and the default action is \c
nextWrite.
Currently the following action types are supported:
- noWriteNow
- writeNow
- nextWrite
Examples of function object specification:
\verbatim
stop
{
type stopAtFile;
libs ("libutilityFunctionObjects.so");
}
\endverbatim
will stop the run at the next write after the file "stop" is created in the
case directory.
\verbatim
stop
{
type stopAtFile;
libs ("libutilityFunctionObjects.so");
file "$FOAM_CASE/stop";
action writeNow;
}
\endverbatim
will write the fields and stop the run when the file "stop" is created in
the case directory.
Usage
\table
Property | Description | Required | Default value
type | type name: stopAtFile | yes |
file | Trigger file path name | no | $FOAM_CASE/<name>
action | Action executed | no | nextWrite
\endtable
The new multiphaseEulerFoam is based on reactingMultiphaseEulerFoam with some
improvements and rationalisation to assist maintenance and further development.
The phase system solution has been enhanced to handle two phases more
effectively and all two-phase specific models updated for compatibility so that
multiphaseEulerFoam can also replace reactingTwoPhaseEulerFoam.
When running multiphaseEulerFoam with only two-phases the default behaviour is
to solve for both phase-fractions but optionally a reference phase can be
specified so that only the other phase-fraction is solved, providing better
compatibility with the behaviour of reactingTwoPhaseEulerFoam.
All reactingMultiphaseEulerFoam and reactingTwoPhaseEulerFoam tutorials have
been updated for multiphaseEulerFoam.
Description
This functionObject writes the phase-fraction map field alpha.map with
incremental value ranges for each phase
e.g., with values 0-1 for water, 1-2 for air, 2-3 for oil etc.
Example of function object specification:
\verbatim
phaseMap
{
type phaseMap;
libs ("libreactingEulerFoamFunctionObjects.so");
writeControl writeTime;
}
\endverbatim
Usage
\table
Property | Description | Required | Default value
type | type name: phaseMap | yes |
\endtable
This replaces the alphas functionality previously built-in to
reactingMultiphaseEulerFoam so that the storage, calculation and writing of the
phase map field is now under user control.
providing the shear-stress term in the momentum equation for incompressible and
compressible Newtonian, non-Newtonian and visco-elastic laminar flow as well as
Reynolds averaged and large-eddy simulation of turbulent flow.
The general deviatoric shear-stress term provided by the MomentumTransportModels
library is named divDevTau for compressible flow and divDevSigma (sigma =
tau/rho) for incompressible flow, the spherical part of the shear-stress is
assumed to be either included in the pressure or handled separately. The
corresponding stress function sigma is also provided which in the case of
Reynolds stress closure returns the effective Reynolds stress (including the
laminar contribution) or for other Reynolds averaged or large-eddy turbulence
closures returns the modelled Reynolds stress or sub-grid stress respectively.
For visco-elastic flow the sigma function returns the effective total stress
including the visco-elastic and Newtonian contributions.
For thermal flow the heat-flux generated by thermal diffusion is now handled by
the separate ThermophysicalTransportModels library allowing independent run-time
selection of the heat-flux model.
During the development of the MomentumTransportModels library significant effort
has been put into rationalising the components and supporting libraries,
removing redundant code, updating names to provide a more logical, consistent
and extensible interface and aid further development and maintenance. All
solvers and tutorials have been updated correspondingly and backward
compatibility of the input dictionaries provided.
Henry G. Weller
CFD Direct Ltd.
Rather than specifying the controls per field it is simpler to use a single set
of controls for all the fields in the list and use separate instances of the
fieldAverage functionObject for different control sets:
Example of function object specification setting all the optional parameters:
fieldAverage1
{
type fieldAverage;
libs ("libfieldFunctionObjects.so");
writeControl writeTime;
restartOnRestart false;
restartOnOutput false;
periodicRestart false;
restartPeriod 0.002;
base time;
window 10.0;
windowName w1;
mean yes;
prime2Mean yes;
fields (U p);
}
This allows for a simple specification with the optional prime2Mean entry using
#includeFunc fieldAverage(U, p, prime2Mean = yes)
or if the prime2Mean is not needed just
#includeFunc fieldAverage(U, p)
to support the more convenient #includeFunc specification in both
#includeFunc fieldAverage(U.air, U.water, alpha.air, p)
and
#includeFunc fieldAverage(fields = (U.air, U.water, alpha.air, p))
forms.
The mean, prime2Mean and base now have default values:
{
mean on; // (default = on)
prime2Mean on; // (default = off)
base time; // time or iteration (default = time)
window 200; // optional averaging window
windowName w1; // optional window name (default = "")
}
so for the majority of cases for which these defaults are appropriate the
fieldAverage functionObject can now be specified in the functions entry in
controlDict thus:
functions
{
fieldAverage1
{
#includeEtc "caseDicts/postProcessing/fields/fieldAverage.cfg"
fields
(
U.air
U.water
alpha.air
p
);
}
}
also utilising the new fieldAverage.cfg file.
For cases in which these defaults are not appropriate, e.g. the prime2Mean is
also required the optional entries can be specified within sub-dictionaries for
each field, e.g.
fieldAverage1
{
#includeEtc "caseDicts/postProcessing/fields/fieldAverage.cfg"
fields
(
U
{
prime2Mean yes;
}
p
{
prime2Mean yes;
}
);
}
The total enthalpy is calculated as
Ha = ha + K
where
ha is absolute enthalpy
K is the kinetic energy: 1/2*magSqr(U)
The total enthalpy or a particular phase can be calculated by specifying the
optional "phase" name, e.g.
#includeFunc totalEnthalpy(phase = liquid)
This change formalises the usage of the "log" keyword in function
objects. By default, logging to stdout is activated when running
"postProcess" or "<solver> -postProcess", and deactivated when a
function is being executed as part of a run.
This behaviour can now be overridden in the function object dictionary
when operating in either mode.
e.g. given a vol pressure field p
functions
{
// Interpolate the pressure field to the faces
surfacep
{
type surfaceInterpolate;
libs ("libfieldFunctionObjects.so");
fields ((p surfacep));
writeControl none;
}
// Average the surface pressure field over the centre faceZone
#includeFunc faceZoneAverage(name=centre, surfacep)
.
.
.
}
Both the functionObject call context (the command line for postProcess, and the
controlDict path for run-time post-precessing) and the configuration file
context where the arguments are substituted are now printed in the error
message, e.g.
postProcess -func 'patchAverage(name=inlet, ields=(p U))'
generates the message
--> FOAM FATAL IO ERROR:
Essential value for keyword 'fields' not set in function entry
patchAverage(name=inlet, ields=(p U))
in command line postProcess -func patchAverage(name=inlet, ields=(p U))
Placeholder value is <field_names>
file: /home/dm2/henry/OpenFOAM/OpenFOAM-dev/etc/caseDicts/postProcessing/surfaceFieldValue/patchAverage from line 13 to line 17.
and with the following in controlDict
functions
{
#includeFunc patchAverage(name=inlet, ields=(p U))
}
generates the message
--> FOAM FATAL IO ERROR:
Essential value for keyword 'fields' not set in function entry
patchAverage(name=inlet, ields=(p U))
in file /home/dm2/henry/OpenFOAM/OpenFOAM-dev/tutorials/incompressible/pimpleFoam/RAS/pitzDaily/system/controlDict at line 55
Placeholder value is <field_names>
file: /home/dm2/henry/OpenFOAM/OpenFOAM-dev/etc/caseDicts/postProcessing/surfaceFieldValue/patchAverage from line 13 to line 17.
This is like the scalarTrasport function except that the transported
scalar is confined to a single phase of a multiphase simulation. In
addition to the usual specification for the scalarTransport function
(i.e., a field, schemes and solution parameters), the user needs to
specify the phase-flux or a pressure field which can be used to generate
it.
Example usage for interFoam:
phaseScalarTransport1
{
type phaseScalarTransport;
libs ("libsolverFunctionObjects.so");
field s.water;
p p_rgh;
}
Example usage for reactingTwoPhaseEulerFoam:
phaseScalarTransport1
{
type phaseScalarTransport;
libs ("libsolverFunctionObjects.so");
field s.water;
alphaPhi alphaRhoPhi.water;
rho thermo:rho.water;
}
The function will write out both the per-unit-phase field that is solved
for (s.water in the above examples) and also the mixture-total field
(alphaS.water), which is often more convenient for post-processing.
to rationalise the structure and class names to avoid the need for the confusing
addNamedToRunTimeSelectionTable and use instead use the standard
addToRunTimeSelectionTable to populate the run-time selection table.
This object calculates a field of the age of fluid in the domain; i.e.,
the time taken for a fluid particle to travel to a location from an
inlet. It outputs a field, named age, with dimensions of time, and
requires a solver and a div(phi,age) scheme to be specified. A number of
corrections for the solution procedure can be set, as well as the name
of the flux and density fields.
Example specification:
age1
{
type age;
libs ("libfieldFunctionObjects.so");
nCorr 10;
phi phi;
rho rho;
}
Example usage:
postProcess -func age -fields "(phi)" -latestTime
This work was supported by Robert Secor and Lori Holmes, at 3M
Description
Calculates the natural logarithm of the specified scalar field.
Performs \f$ln(max(x, a))\f$ where \f$x\f$ is the field and \f$a\f$ an
optional clip to handle 0 or negative \f$x\f$.
The etc/caseDicts/postProcessing/fields/log configuration file is provided so
that the simple #includeFunc can be used to execute this functionObject during
the run, e.g. for some dimensionless field x
functions
{
#includeFunc log(x)
}
or if x might be 0 or negative in some regions the optional clip may be applied:
functions
{
#includeFunc log(p,clip=1e-6)
}
The sampled sets have been renamed in a more explicit and consistent
manner, and two new ones have also been added. The available sets are as
follows:
arcUniform: Uniform samples along an arc. Replaces "circle", and
adds the ability to sample along only a part of the circle's
circumference. Example:
{
type arcUniform;
centre (0.95 0 0.25);
normal (1 0 0);
radial (0 0 0.25);
startAngle -1.57079633;
endAngle 0.52359878;
nPoints 200;
axis x;
}
boundaryPoints: Specified point samples associated with a subset of
the boundary. Replaces "patchCloud". Example:
{
type boundaryPoints;
patches (inlet1 inlet2);
points ((0 -0.05 0.05) (0 -0.05 0.1) (0 -0.05 0.15));
maxDistance 0.01;
axis x;
}
boundaryRandom: Random samples within a subset of the boundary.
Replaces "patchSeed", but changes the behaviour to be entirely
random. It does not seed the boundary face centres first. Example:
{
type boundaryRandom;
patches (inlet1 inlet2);
nPoints 1000;
axis x;
}
boxUniform: Uniform grid of samples within a axis-aligned box.
Replaces "array". Example:
{
type boxUniform;
box (0.95 0 0.25) (1.2 0.25 0.5);
nPoints (2 4 6);
axis x;
}
circleRandom: Random samples within a circle. New. Example:
{
type circleRandom;
centre (0.95 0 0.25);
normal (1 0 0);
radius 0.25;
nPoints 200;
axis x;
}
lineFace: Face-intersections along a line. Replaces "face". Example:
{
type lineFace;
start (0.6 0.6 0.5);
end (0.6 -0.3 -0.1);
axis x;
}
lineCell: Cell-samples along a line at the mid-points in-between
face-intersections. Replaces "midPoint". Example:
{
type lineCell;
start (0.5 0.6 0.5);
end (0.5 -0.3 -0.1);
axis x;
}
lineCellFace: Combination of "lineFace" and "lineCell". Replaces
"midPointAndFace". Example:
{
type lineCellFace;
start (0.55 0.6 0.5);
end (0.55 -0.3 -0.1);
axis x;
}
lineUniform: Uniform samples along a line. Replaces "uniform".
Example:
{
type lineUniform;
start (0.65 0.3 0.3);
end (0.65 -0.3 -0.1);
nPoints 200;
axis x;
}
points: Specified points. Replaces "cloud" when the ordered flag is
false, and "polyLine" when the ordered flag is true. Example:
{
type points;
points ((0 -0.05 0.05) (0 -0.05 0.1) (0 -0.05 0.15));
ordered yes;
axis x;
}
sphereRandom: Random samples within a sphere. New. Example:
{
type sphereRandom;
centre (0.95 0 0.25);
radius 0.25;
nPoints 200;
axis x;
}
triSurfaceMesh: Samples from all the points of a triSurfaceMesh.
Replaces "triSurfaceMeshPointSet". Example:
{
type triSurfaceMesh;
surface "surface.stl";
axis x;
}
The headers have also had documentation added. Example usage and a
description of the control parameters now exists for all sets.
In addition, a number of the algorithms which generate the sets have
been refactored or rewritten. This was done either to take advantage of
the recent changes to random number generation, or to remove ad-hoc
fixes that were made unnecessary by the barycentric tracking algorithm.
Streamlines can now be tracked in both directions from the set of
initial locations. The keyword controlling this behaviour is
"direction", which can be set to "forward", "backward" or "both".
This new keyword superseeds the "trackForward" entry, which has been
retained for backwards compatibility.
Description
Evaluates and writes the turbulence intensity field 'I'.
The turbulence intensity field 'I' is the root-mean-square of the turbulent
velocity fluctuations normalised by the local velocity magnitude:
\f[
I \equiv \frac{\sqrt{\frac{2}{3}\, k}}{U}
\f]
To avoid spurious extrema and division by 0 I is limited to 1 where the
velocity magnitude is less than the turbulent velocity fluctuations.
Example of function object specification:
\verbatim
functions
{
.
.
.
turbulenceIntensity
{
type turbulenceIntensity;
libs ("libfieldFunctionObjects.so");
}
.
.
.
}
\endverbatim
or using the standard configuration file:
\verbatim
functions
{
.
.
.
#includeFunc turbulenceIntensity
.
.
.
}
\endverbatim
and optionally the CPU and clock times per time step.
Example of function object specification:
time
{
type time;
libs ("libutilityFunctionObjects.so");
writeControl timeStep;
writeInterval 1;
perTimeStep no;
}
Adding
#includeFunc time
to the functions list in the controlDict of the motorBike tutorial generates
0 1.190000e+00 1
1 1.640000e+00 1
2 1.940000e+00 2
Enabling the optional writing of the CPU and clock time per time step is
straight forward:
#includeFunc time(perTimeStep=yes)
