Mesh motion and topology change are now combinable run-time selectable options
within fvMesh, replacing the restrictive dynamicFvMesh which supported only
motion OR topology change.
All solvers which instantiated a dynamicFvMesh now instantiate an fvMesh which
reads the optional constant/dynamicFvMeshDict to construct an fvMeshMover and/or
an fvMeshTopoChanger. These two are specified within the optional mover and
topoChanger sub-dictionaries of dynamicFvMeshDict.
When the fvMesh is updated the fvMeshTopoChanger is first executed which can
change the mesh topology in anyway, adding or removing points as required, for
example for automatic mesh refinement/unrefinement, and all registered fields
are mapped onto the updated mesh. The fvMeshMover is then executed which moved
the points only and calculates the cell volume change and corresponding
mesh-fluxes for conservative moving mesh transport. If multiple topological
changes or movements are required these would be combined into special
fvMeshMovers and fvMeshTopoChangers which handle the processing of a list of
changes, e.g. solidBodyMotionFunctions:multiMotion.
The tutorials/multiphase/interFoam/laminar/sloshingTank3D3DoF case has been
updated to demonstrate this new functionality by combining solid-body motion
with mesh refinement/unrefinement:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: dev
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class dictionary;
location "constant";
object dynamicMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
mover
{
type motionSolver;
libs ("libfvMeshMovers.so" "libfvMotionSolvers.so");
motionSolver solidBody;
solidBodyMotionFunction SDA;
CofG (0 0 0);
lamda 50;
rollAmax 0.2;
rollAmin 0.1;
heaveA 4;
swayA 2.4;
Q 2;
Tp 14;
Tpn 12;
dTi 0.06;
dTp -0.001;
}
topoChanger
{
type refiner;
libs ("libfvMeshTopoChangers.so");
// How often to refine
refineInterval 1;
// Field to be refinement on
field alpha.water;
// Refine field in between lower..upper
lowerRefineLevel 0.001;
upperRefineLevel 0.999;
// Have slower than 2:1 refinement
nBufferLayers 1;
// Refine cells only up to maxRefinement levels
maxRefinement 1;
// Stop refinement if maxCells reached
maxCells 200000;
// Flux field and corresponding velocity field. Fluxes on changed
// faces get recalculated by interpolating the velocity. Use 'none'
// on surfaceScalarFields that do not need to be reinterpolated.
correctFluxes
(
(phi none)
(nHatf none)
(rhoPhi none)
(alphaPhi.water none)
(meshPhi none)
(meshPhi_0 none)
(ghf none)
);
// Write the refinement level as a volScalarField
dumpLevel true;
}
// ************************************************************************* //
Note that currently this is the only working combination of mesh-motion with
topology change within the new framework and further development is required to
update the set of topology changers so that topology changes with mapping are
separated from the mesh-motion so that they can be combined with any of the
other movements or topology changes in any manner.
All of the solvers and tutorials have been updated to use the new form of
dynamicMeshDict but backward-compatibility was not practical due to the complete
reorganisation of the mesh change structure.
The calculation and input/output of transformations has been rewritten
for all coupled patches. This replaces multiple duplicated, inconsistent
and incomplete implementations of transformation handling which were
spread across the different coupled patch types.
Transformations are now calculated or specified once, typically during
mesh construction or manipulation, and are written out with the boundary
data. They are never re-calculated. Mesh changes should not change the
transformation across a coupled interface; to do so would violate the
transformation.
Transformations are now calculated using integral properties of the
patches. This is more numerically stable that the previous methods which
functioned in terms of individual faces. The new routines are also able
to automatically calculate non-zero centres of rotation.
The user input of transformations is backwards compatible, and permits
the user to manually specify varying amounts of the transformation
geometry. Anything left unspecified gets automatically computed from the
patch geometry. Supported specifications are:
1) No specification. Transformations on cyclics are automatically
generated, and cyclicAMI-type patches assume no transformation. For
example (in system/blockMeshDict):
cyclicLeft
{
type cyclic;
neighbourPatch cyclicRight;
faces ((0 1 2 3));
}
cyclicRight
{
type cyclic;
neighbourPatch cyclicLeft;
faces ((4 5 6 7));
}
2) Partial specification. The type of transformation is specified
by the user, as well as the coordinate system if the transform is
rotational. The rotation angle or separation vector is still
automatically generated. This form is useful as the signs of the
angle and separation are opposite on different sides of an interface
and can be difficult to specify correctly. For example:
cyclicLeft
{
type cyclic;
neighbourPatch cyclicRight;
transformType translational;
faces ((0 1 2 3));
}
cyclicRight
{
type cyclic;
neighbourPatch cyclicLeft;
transformType translational;
faces ((4 5 6 7));
}
cyclicAMILeft
{
type cyclicAMI;
neighbourPatch cyclicAMIRight;
transformType rotational;
rotationAxis (0 0 1);
rotationCentre (0.05 -0.01 0);
faces ((8 9 10 11));
}
cyclicAMIRight
{
type cyclicAMI;
neighbourPatch cyclicAMILeft;
transformType rotational;
rotationAxis (0 0 1);
rotationCentre (0.05 -0.01 0);
faces ((12 13 14 15));
}
3) Full specification. All parameters of the transformation are
given. For example:
cyclicLeft
{
type cyclic;
neighbourPatch cyclicRight;
transformType translational;
separaion (-0.01 0 0);
faces ((0 1 2 3));
}
cyclicRight
{
type cyclic;
neighbourPatch cyclicLeft;
transformType translational;
separaion (0.01 0 0);
faces ((4 5 6 7));
}
cyclicAMILeft
{
type cyclicAMI;
neighbourPatch cyclicAMIRight;
transformType rotational;
rotationAxis (0 0 1);
rotationCentre (0.05 -0.01 0);
rotationAngle 60;
faces ((8 9 10 11));
}
cyclicAMIRight
{
type cyclicAMI;
neighbourPatch cyclicAMILeft;
transformType rotational;
rotationAxis (0 0 1);
rotationCentre (0.05 -0.01 0);
rotationAngle 60;
faces ((12 13 14 15));
}
Automatic ordering of faces and points across coupled patches has also
been rewritten, again replacing multiple unsatisfactory implementations.
The new ordering method is more robust on poor meshes as it
geometrically matches only a single face (per contiguous region of the
patch) in order to perform the ordering, and this face is chosen to be
the one with the highest quality. A failure in ordering now only occurs
if the best face in the patch cannot be geometrically matched, whether
as previously the worst face could cause the algorithm to fail.
The oldCyclicPolyPatch has been removed, and the mesh converters which
previously used it now all generate ordered cyclic and baffle patches
directly. This removes the need to run foamUpgradeCyclics after
conversion. In addition the fluent3DMeshToFoam converter now supports
conversion of periodic/shadow pairs to OpenFOAM cyclic patches.
Replaced all uses of complex Xfer class with C++11 "move" constructors and
assignment operators. Removed the now redundant Xfer class.
This substantial changes improves consistency between OpenFOAM and the C++11 STL
containers and algorithms, reduces memory allocation and copy overhead when
returning containers from functions and simplifies maintenance of the core
libraries significantly.
Using the new field mapper framework it is now possible to create specialised
mappers rather than creating a fatter and fatter interface in the base mapper.
This approach is far more extensible, comprehensible and maintainable.
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.
splitMeshRegions: handle flipping of faces for surface fields
subsetMesh: subset dimensionedFields
decomposePar: use run-time selection of decomposition constraints. Used to
keep cells on particular processors. See the decomposeParDict in
$FOAM_UTILITIES/parallel/decomposePar:
- preserveBaffles: keep baffle faces on same processor
- preserveFaceZones: keep faceZones owner and neighbour on same processor
- preservePatches: keep owner and neighbour on same processor. Note: not
suitable for cyclicAMI since these are not coupled on the patch level
- singleProcessorFaceSets: keep complete faceSet on a single processor
- refinementHistory: keep cells originating from a single cell on the
same processor.
decomposePar: clean up decomposition of refinement data from snappyHexMesh
reconstructPar: reconstruct refinement data (refineHexMesh, snappyHexMesh)
reconstructParMesh: reconstruct refinement data (refineHexMesh, snappyHexMesh)
redistributePar:
- corrected mapping surfaceFields
- adding processor patches in order consistent with decomposePar
argList: check that slaves are running same version as master
fvMeshSubset: move to dynamicMesh library
fvMeshDistribute:
- support for mapping dimensionedFields
- corrected mapping of surfaceFields
parallel routines: allow parallel running on single processor
Field: support for
- distributed mapping
- mapping with flipping
mapDistribute: support for flipping
AMIInterpolation: avoid constructing localPoints
