With fvMeshTopoChangers::meshToMesh it is now possible to map the solution to a
specified sequence of pre-generated meshes at run-time to support arbitrary mesh
changes, refinements, un-refinements, changes in region topology, geometry,
etc. Additionally mesh-motion between the sequence of meshes is supported to
allow for e.g. piston and valve motion in engines.
The tutorials/incompressible/pimpleFoam/laminar/movingCone case has been updated
to provide a demonstration of the advantages of this run-time mesh-mapping by
mapping to meshes that are finer behind the cone and coarser in front of the
cone as the cone approaches the end of the domain, thus maintaining good
resolution while avoiding excessive cell aspect ratio as the mesh is squeezed.
The dynamicMeshDict for the movingCone case is;
mover
{
type motionSolver;
libs ("libfvMeshMovers.so" "libfvMotionSolvers.so");
motionSolver velocityComponentLaplacian;
component x;
diffusivity directional (1 200 0);
}
topoChanger
{
type meshToMesh;
libs ("libmeshToMeshTopoChanger.so");
times (0.0015 0.003);
timeDelta 1e-6;
}
which lists the mesh mapping times 0.0015s 0.003s and meshes for these times in
directories constant/meshToMesh_0.0015 and constant/meshToMesh_0.003 are
generated in the Allrun script before the pimpleFoam run:
runApplication -a blockMesh -dict blockMeshDict.2
rm -rf constant/meshToMesh_0.0015
mkdir constant/meshToMesh_0.0015
mv constant/polyMesh constant/meshToMesh_0.0015
runApplication -a blockMesh -dict blockMeshDict.3
rm -rf constant/meshToMesh_0.003
mkdir constant/meshToMesh_0.003
mv constant/polyMesh constant/meshToMesh_0.003
runApplication -a blockMesh -dict blockMeshDict.1
runApplication $application
Note: This functionality is experimental and has only undergone basic testing.
It is likely that it does not yet work with all functionObject, fvModels
etc. which will need updating to support this form of mesh topology change.
This new mapping structure is designed to support run-time mesh-to-mesh mapping
to allow arbitrary changes to the mesh structure, for example during extreme
motion requiring significant topology change including region disconnection etc.
The polyTopoChangeMap is the map specifically relating to polyMesh topological
changes generated by polyTopoChange and used to update and map mesh related
types and fields following the topo-change.
This is a map data structure rather than a class or function which performs the
mapping operation so polyMeshDistributionMap is more logical and comprehensible
than mapDistributePolyMesh.
Sampled sets and streamlines now write all their fields to the same
file. This prevents excessive duplication of the geometry and makes
post-processing tasks more convenient.
"axis" entries are now optional in sampled sets and streamlines. When
omitted, a default entry will be used, which is chosen appropriately for
the coordinate set and the write format. Some combinations are not
supported. For example, a scalar ("x", "y", "z" or "distance") axis
cannot be used to write in the vtk format, as vtk requires 3D locations
with which to associate data. Similarly, a point ("xyz") axis cannot be
used with the gnuplot format, as gnuplot needs a single scalar to
associate with the x-axis.
Streamlines can now write out fields of any type, not just scalars and
vectors, and there is no longer a strict requirement for velocity to be
one of the fields.
Streamlines now output to postProcessing/<functionName>/time/<file> in
the same way as other functions. The additional "sets" subdirectory has
been removed.
The raw set writer now aligns columns correctly.
The handling of segments in coordSet and sampledSet has been
fixed/completed. Segments mean that a coordinate set can represent a
number of contiguous lines, disconnected points, or some combination
thereof. This works in parallel; segments remain contiguous across
processor boundaries. Set writers now only need one write method, as the
previous "writeTracks" functionality is now handled by streamlines
providing the writer with the appropriate segment structure.
Coordinate sets and set writers now have a convenient programmatic
interface. To write a graph of A and B against some coordinate X, in
gnuplot format, we can call the following:
setWriter::New("gnuplot")->write
(
directoryName,
graphName,
coordSet(true, "X", X), // <-- "true" indicates a contiguous
"A", // line, "false" would mean
A, // disconnected points
"B",
B
);
This write function is variadic. It supports any number of
field-name-field pairs, and they can be of any primitive type.
Support for Jplot and Xmgrace formats has been removed. Raw, CSV,
Gnuplot, VTK and Ensight formats are all still available.
The old "graph" functionality has been removed from the code, with the
exception of the randomProcesses library and associated applications
(noise, DNSFoam and boxTurb). The intention is that these should also
eventually be converted to use the setWriters. For now, so that it is
clear that the "graph" functionality is not to be used elsewhere, it has
been moved into a subdirectory of the randomProcesses library.
By default a streamline now stops at the cyclic and starts again at the
coupled location on the opposite cyclic.
There is also now an "outside" option that can be passed to the
streamlines function. This changes the default behaviour so that the
streamline continues outside of the mesh when it encounters a cyclic
patch. The following postProcess command uses the "outside" option in
this way:
postProcess -latestTime -func "
streamlinesPatch
(
patch=inlet,
nPoints=50,
outside=true,
fields=(p U)
)"
With this change each functionObject provides the list of fields required so
that the postProcess utility can pre-load them before executing the list of
functionObjects. This provides a more convenient interface than using the
-field or -fields command-line options to postProcess which are now redundant.
