When an OpenFOAM simulation runs in parallel, the data for decomposed fields and
mesh(es) has historically been stored in multiple files within separate
directories for each processor. Processor directories are named 'processorN',
where N is the processor number.
This commit introduces an alternative "collated" file format where the data for
each decomposed field (and mesh) is collated into a single file, which is
written and read on the master processor. The files are stored in a single
directory named 'processors'.
The new format produces significantly fewer files - one per field, instead of N
per field. For large parallel cases, this avoids the restriction on the number
of open files imposed by the operating system limits.
The file writing can be threaded allowing the simulation to continue running
while the data is being written to file. NFS (Network File System) is not
needed when using the the collated format and additionally, there is an option
to run without NFS with the original uncollated approach, known as
"masterUncollated".
The controls for the file handling are in the OptimisationSwitches of
etc/controlDict:
OptimisationSwitches
{
...
//- Parallel IO file handler
// uncollated (default), collated or masterUncollated
fileHandler uncollated;
//- collated: thread buffer size for queued file writes.
// If set to 0 or not sufficient for the file size threading is not used.
// Default: 2e9
maxThreadFileBufferSize 2e9;
//- masterUncollated: non-blocking buffer size.
// If the file exceeds this buffer size scheduled transfer is used.
// Default: 2e9
maxMasterFileBufferSize 2e9;
}
When using the collated file handling, memory is allocated for the data in the
thread. maxThreadFileBufferSize sets the maximum size of memory in bytes that
is allocated. If the data exceeds this size, the write does not use threading.
When using the masterUncollated file handling, non-blocking MPI communication
requires a sufficiently large memory buffer on the master node.
maxMasterFileBufferSize sets the maximum size in bytes of the buffer. If the
data exceeds this size, the system uses scheduled communication.
The installation defaults for the fileHandler choice, maxThreadFileBufferSize
and maxMasterFileBufferSize (set in etc/controlDict) can be over-ridden within
the case controlDict file, like other parameters. Additionally the fileHandler
can be set by:
- the "-fileHandler" command line argument;
- a FOAM_FILEHANDLER environment variable.
A foamFormatConvert utility allows users to convert files between the collated
and uncollated formats, e.g.
mpirun -np 2 foamFormatConvert -parallel -fileHandler uncollated
An example case demonstrating the file handling methods is provided in:
$FOAM_TUTORIALS/IO/fileHandling
The work was undertaken by Mattijs Janssens, in collaboration with Henry Weller.
Updated the tetrahedron and triangle classes to use the barycentric
primitives. Removed duplicate code for generating random positions in
tets and tris, and fixed bug in tri random position.
for consistency with reactingTwoPhaseEulerFoam and to ensure correct operation
of models requiring formal boundedness of phase-fractions.
Resolves bug-report https://bugs.openfoam.org/view.php?id=2589
"pos" now returns 1 if the argument is greater than 0, otherwise it returns 0.
This is consistent with the common mathematical definition of the "pos" function:
https://en.wikipedia.org/wiki/Sign_(mathematics)
However the previous implementation in which 1 was also returned for a 0
argument is useful in many situations so the "pos0" has been added which returns
1 if the argument is greater or equal to 0. Additionally the "neg0" has been
added which returns 1 if if the argument is less than or equal to 0.
Temporal variation of Ta is generally more useful than spatial variation but
a run-time switch between the two modes of operation could be implemented in
needed.
Initially the listSwitches functions depended directly on argList functionality
but this has now been factored out so that the listSwitches functions are more
general and require only debug functionality.
Provides better context for the available boundary conditions, fvOptions,
functionObjects etc. and thus returns only those available to and compatible
with the particular application.
e.g.
pimpleFoam -help
Usage: pimpleFoam [OPTIONS]
options:
-case <dir> specify alternate case directory, default is the cwd
-listFunctionObjects
List functionObjects
-listFvOptions List fvOptions
-listRegisteredSwitches
List switches registered for run-time modification
-listScalarBCs List scalar field boundary conditions (fvPatchField<scalar>)
-listSwitches List switches declared in libraries but not set in
etc/controlDict
-listTurbulenceModels
List turbulenceModels
-listUnsetSwitches
List switches declared in libraries but not set in
etc/controlDict
-listVectorBCs List vector field boundary conditions (fvPatchField<vector>)
-noFunctionObjects
do not execute functionObjects
-parallel run in parallel
-postProcess Execute functionObjects only
-roots <(dir1 .. dirN)>
slave root directories for distributed running
-srcDoc display source code in browser
-doc display application documentation in browser
-help print the usage
pimpleFoam listTurbulenceModels
pimpleFoam -listTurbulenceModels
/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: dev |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : dev-39c46019e44f
Exec : pimpleFoam -listTurbulenceModels
Date : Jun 10 2017
Time : 21:37:49
Host : "dm"
PID : 675
Case : /home/dm2/henry/OpenFOAM/OpenFOAM-dev
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
SetNaN : Initialising allocated memory to NaN (FOAM_SETNAN).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Turbulence models
3
(
LES
RAS
laminar
)
RAS models
18
(
LRR
LamBremhorstKE
LaunderSharmaKE
LienCubicKE
LienLeschziner
RNGkEpsilon
SSG
ShihQuadraticKE
SpalartAllmaras
kEpsilon
kOmega
kOmegaSST
kOmegaSSTLM
kOmegaSSTSAS
kkLOmega
qZeta
realizableKE
v2f
)
LES models
10
(
DeardorffDiffStress
Smagorinsky
SpalartAllmarasDDES
SpalartAllmarasDES
SpalartAllmarasIDDES
WALE
dynamicKEqn
dynamicLagrangian
kEqn
kOmegaSSTDES
)
Further work will be needed to support the -listTurbulenceModels option in
multiphase solvers.
vectorField or vector2DField from scalarField components. To do this
properly and have it work for field-type combinations would require some
new field function macros.
now possible with level-sets as well as planes. Removed tetPoints class
as this wasn't really used anywhere except for the old tet-cutting
routines. Restored tetPointRef.H to be consistent with other primitive
shapes. Re-wrote tet-overlap mapping in terms of the new cutting.
In addition to local Doxygen HTML directories an optional HTTP server directory
may be specified:
Documentation
{
docBrowser "firefox";
doxyDocDirs
(
"$WM_PROJECT_USER_DIR/html"
"~OpenFOAM/html"
"$WM_PROJECT_DIR/doc/Doxygen/html"
"http://cpp.openfoam.org/dev"
);
doxySourceFileExt "_8C.html";
}
from which the Doxygen documentation files may be obtained so now the "-doc"
command-line option may be used even if if Doxygen has not been run locally,
e.g.
pimpleFoam -doc
terms of the local barycentric coordinates of the current tetrahedron,
rather than the global coordinate system.
Barycentric tracking works on any mesh, irrespective of mesh quality.
Particles do not get "lost", and tracking does not require ad-hoc
"corrections" or "rescues" to function robustly, because the calculation
of particle-face intersections is unambiguous and reproducible, even at
small angles of incidence.
Each particle position is defined by topology (i.e. the decomposed tet
cell it is in) and geometry (i.e. where it is in the cell). No search
operations are needed on restart or reconstruct, unlike when particle
positions are stored in the global coordinate system.
The particle positions file now contains particles' local coordinates
and topology, rather than the global coordinates and cell. This change
to the output format is not backwards compatible. Existing cases with
Lagrangian data will not restart, but they will still run from time
zero without any modification. This change was necessary in order to
guarantee that the loaded particle is valid, and therefore
fundamentally prevent "loss" and "search-failure" type bugs (e.g.,
2517, 2442, 2286, 1836, 1461, 1341, 1097).
The tracking functions have also been converted to function in terms
of displacement, rather than end position. This helps remove floating
point error issues, particularly towards the end of a tracking step.
Wall bounded streamlines have been removed. The implementation proved
incompatible with the new tracking algorithm. ParaView has a surface
LIC plugin which provides equivalent, or better, functionality.
Additionally, bug report <https://bugs.openfoam.org/view.php?id=2517>
is resolved by this change.
except turbulence and lagrangian which will also be updated shortly.
For example in the nonNewtonianIcoFoam offsetCylinder tutorial the viscosity
model coefficients may be specified in the corresponding "<type>Coeffs"
sub-dictionary:
transportModel CrossPowerLaw;
CrossPowerLawCoeffs
{
nu0 [0 2 -1 0 0 0 0] 0.01;
nuInf [0 2 -1 0 0 0 0] 10;
m [0 0 1 0 0 0 0] 0.4;
n [0 0 0 0 0 0 0] 3;
}
BirdCarreauCoeffs
{
nu0 [0 2 -1 0 0 0 0] 1e-06;
nuInf [0 2 -1 0 0 0 0] 1e-06;
k [0 0 1 0 0 0 0] 0;
n [0 0 0 0 0 0 0] 1;
}
which allows a quick change between models, or using the simpler
transportModel CrossPowerLaw;
nu0 [0 2 -1 0 0 0 0] 0.01;
nuInf [0 2 -1 0 0 0 0] 10;
m [0 0 1 0 0 0 0] 0.4;
n [0 0 0 0 0 0 0] 3;
if quick switching between models is not required.
To support this more convenient parameter specification the inconsistent
specification of seedSampleSet in the streamLine and wallBoundedStreamLine
functionObjects had to be corrected from
// Seeding method.
seedSampleSet uniform; //cloud; //triSurfaceMeshPointSet;
uniformCoeffs
{
type uniform;
axis x; //distance;
// Note: tracks slightly offset so as not to be on a face
start (-1.001 -0.05 0.0011);
end (-1.001 -0.05 1.0011);
nPoints 20;
}
to the simpler
// Seeding method.
seedSampleSet
{
type uniform;
axis x; //distance;
// Note: tracks slightly offset so as not to be on a face
start (-1.001 -0.05 0.0011);
end (-1.001 -0.05 1.0011);
nPoints 20;
}
which also support the "<type>Coeffs" form
// Seeding method.
seedSampleSet
{
type uniform;
uniformCoeffs
{
axis x; //distance;
// Note: tracks slightly offset so as not to be on a face
start (-1.001 -0.05 0.0011);
end (-1.001 -0.05 1.0011);
nPoints 20;
}
}
These models have been particularly designed for use in the VoF solvers, both
incompressible and compressible. Currently constant and temperature dependent
surface tension models are provided but it easy to write models in which the
surface tension is evaluated from any fields held by the mesh database.
For example in the potentialFreeSurfaceFoam/oscillatingBox tutorial it is
cleaner to apply the "linearRamp" function to the "sine" function rather than
using an amplitude table:
floatingObject
{
type fixedNormalInletOutletVelocity;
fixTangentialInflow false;
normalVelocity
{
type uniformFixedValue;
uniformValue
{
type scale;
value
{
type sine;
frequency 1;
amplitude 0.025;
scale (0 1 0);
level (0 0 0);
}
scale
{
type linearRamp;
duration 10;
}
}
}
value uniform (0 0 0);
}
Description
Ramp function base class for the set of scalar functions starting from 0 and
increasing monotonically to 1 from \c start over the \c duration and
remaining at 1 thereafter.
Usage:
\verbatim
<entryName> <rampFunction>;
<entryName>Coeffs
{
start 10;
duration 20;
}
\endverbatim
or
\verbatim
<entryName>
{
type <rampFunction>;
start 10;
duration 20;
}
\endverbatim
Where:
\table
Property | Description | Required | Default value
start | Start time | no | 0
duration | Duration | yes |
\endtable
The following common ramp functions are provided: linear, quadratic, halfCosine,
quarterCosine and quaterSine, others can easily be added and registered to the run-time
selection system.
e.g.
ramp
{
type quadratic;
start 200;
duration 1.6;
}
but the old format is supported for backward compatibility:
ramp linear;
rampCoeffs
{
start 200;
duration 1.6;
}
Using
decomposePar -copyZero
The mesh is decomposed as usual but the '0' directory is recursively copied to
the 'processor.*' directories rather than decomposing the fields. This is a
convenient option to handle cases where the initial field files are generic and
can be used for serial or parallel running. See for example the
incompressible/simpleFoam/motorBike tutorial case.
Now the interFoam and compressibleInterFoam families of solvers use the same
alphaEqn formulation and supporting all of the MULES options without
code-duplication.
The semi-implicit MULES support allows running with significantly larger
time-steps but this does reduce the interface sharpness.
if convergence is not achieved within the maximum number of iterations.
Sometimes, particularly running in parallel, PBiCG fails to converge or diverges
without warning or obvious cause leaving a solution field containing significant
errors which can cause divergence of the application. PBiCGStab is more robust
and does not suffer from the problems encountered with PBiCG.
