In early versions of OpenFOAM the scalar limits were simple macro replacements and the
names were capitalized to indicate this. The scalar limits are now static
constants which is a huge improvement on the use of macros and for consistency
the names have been changed to camel-case to indicate this and improve
readability of the code:
GREAT -> great
ROOTGREAT -> rootGreat
VGREAT -> vGreat
ROOTVGREAT -> rootVGreat
SMALL -> small
ROOTSMALL -> rootSmall
VSMALL -> vSmall
ROOTVSMALL -> rootVSmall
The original capitalized are still currently supported but their use is
deprecated.
Specifying default fields for complex and multi-phase cases is simplified and
generalized by using wildcards to select sets of related field names, e.g.
defaultFields (p p_rgh U "U\..*" T "T\..*" "alpha\..*");
selects the velocity, temperature and phase-fraction fields of all phases in
addition to the pressure fields.
The default patch types specified in the new defaultPatchTypes entry of the
etc paraFoam configuration dictionaries:
defaultPatchTypes (patch wall);
Wildcards are supported, for example to specify that all patches loaded simply set
defaultPatchTypes to
defaultPatchTypes (".*");
The new default paraFoam configuration is in the files OpenFOAM-dev/etc/paraFoam
containing the entry
defaultFields (U p p_rgh T alpha.water alpha.air);
specifying the set of fields which are loaded by default if available. This
setting maybe overridden by providing additional paraFoam configuration files in
any of the OpenFOAM etc directories searched, listed using
foamEtcFile -list
e.g.
~/.OpenFOAM/dev
~/.OpenFOAM
~/OpenFOAM/site/dev
~/OpenFOAM/site
~/OpenFOAM/OpenFOAM-dev/etc
The new configurable set of default fields loaded replaces the original hard-coded default of
"p" and "U" and is much more convenient for current OpenFOAM usage.
The "Refresh Times" button now triggers a re-render of the visualisation
as well as scanning for new times and fields. This prevents old
overwritten data from remaining on screen despite everything else having
been updated.
ParaView has been updated to version 5.4.0. The C++ panel has been
deleted and replaced with a panel based on the new(er) XML API. This
reader works for ParaView-4.0.1 and newer. The ParaView 3 reader remains
unchanged.
Update issues have also been fixed. All the time directories are now
scanned for fields and clouds when filling the selection lists. This
stops fields from disappearing when the time is changed. The scan is
only done on startup and when the refresh button is pressed.
The list of available Lagrangian fields also now shows a combined set of
all the clouds. Previously, only fields from the first cloud were shown.
If a field does not apply to all the clouds, ParaView will display it's
name in the dropdown menu with a "(partial)" qualifier.
Some undocumented and incomplete bits of code, which were not being
compiled, have been removed.
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:
$FOAM_TUTORIALS/IO/fileHandling
The work was undertaken by Mattijs Janssens, in collaboration with Henry Weller.
e.g.
ramp
{
type quadratic;
start 200;
duration 1.6;
}
but the old format is supported for backward compatibility:
ramp linear;
rampCoeffs
{
start 200;
duration 1.6;
}
For example, to mesh a sphere with a single block the geometry is defined in the
blockMeshDict as a searchableSurface:
geometry
{
sphere
{
type searchableSphere;
centre (0 0 0);
radius 1;
}
}
The vertices, block topology and curved edges are defined in the usual
way, for example
v 0.5773502;
mv -0.5773502;
a 0.7071067;
ma -0.7071067;
vertices
(
($mv $mv $mv)
( $v $mv $mv)
( $v $v $mv)
($mv $v $mv)
($mv $mv $v)
( $v $mv $v)
( $v $v $v)
($mv $v $v)
);
blocks
(
hex (0 1 2 3 4 5 6 7) (10 10 10) simpleGrading (1 1 1)
);
edges
(
arc 0 1 (0 $ma $ma)
arc 2 3 (0 $a $ma)
arc 6 7 (0 $a $a)
arc 4 5 (0 $ma $a)
arc 0 3 ($ma 0 $ma)
arc 1 2 ($a 0 $ma)
arc 5 6 ($a 0 $a)
arc 4 7 ($ma 0 $a)
arc 0 4 ($ma $ma 0)
arc 1 5 ($a $ma 0)
arc 2 6 ($a $a 0)
arc 3 7 ($ma $a 0)
);
which will produce a mesh in which the block edges conform to the sphere
but the faces of the block lie somewhere between the original cube and
the spherical surface which is a consequence of the edge-based
transfinite interpolation.
Now the projection of the block faces to the geometry specified above
can also be specified:
faces
(
project (0 4 7 3) sphere
project (2 6 5 1) sphere
project (1 5 4 0) sphere
project (3 7 6 2) sphere
project (0 3 2 1) sphere
project (4 5 6 7) sphere
);
which produces a mesh that actually conforms to the sphere.
See OpenFOAM-dev/tutorials/mesh/blockMesh/sphere
This functionality is experimental and will undergo further development
and generalization in the future to support more complex surfaces,
feature edge specification and extraction etc. Please get involved if
you would like to see blockMesh become a more flexible block-structured
mesher.
Henry G. Weller, CFD Direct.
- There will be triangles rendered inside the mesh (when
surface-rendering), because one of the cell's triangles is defined
as a quadrangle in VTK_WEDGE.
- Therefore, this VTK_WEDGE representation is only used when
decomposing the mesh, otherwise the correct representation is done
by VTK_POLYHEDRON.
- Furthermore, using VTK_PYRAMID gave worse result, because it renders
2 triangles inside the mesh for the collapsed quadrangle, likely due
to mismatch with the adjacent cell's face.
- Using VTK_HEXAHEDRON was not tested in this iteration, given that it
should give even worse results, when compared to using VTK_PYRAMID.
Patch contributed by Bruno Santos
Resolves bug-report http://bugs.openfoam.org/view.php?id=2099
Now the functionality to write single graph files or log files (vs time)
may be used in the creation of any form of functionObject, not just
those relating to a mesh region.
