Now the HashTable underlying PtrListDictionary is used for zone lookup by name
which is a lot faster than the linear search method used previously if there are
a large number of zones.
Now faceZones are handled directly by the applications and the new
faceZone::topoChange function so that any face can now be in any number of
zones, significantly increasing the flexibility and usefulness of faceZones.
This completes the generalisation of cellZone, faceZone and pointZone to support
multiple zones for each cell, face or point respectively. Next step will be to
make zones polymorphic and run-time selectable so that they can alter during the
run and adapt to moving meshes for example.
For a case extruding patches left and right:
sourcePatches (left right);
if the optional zoneNames entry is also specified in extrudeMeshDict
zoneNames (leftCells rightCells);
the cells extruded from the left patch are added to the leftCells cellZone and
the cells extruded from the right patch are added to the rightCells cellZone.
Alternatively if a single zone name is specified, e.g.
zoneNames (extrudedCells);
then cells extruded from the left and right patches are added to the
extrudedCells cellZone.
If the number of patches to extrude is large it might be more convenient for
the cells extruded from each patch to be added to a cellZone named the same as
each patch, this option is selected by setting zoneNames to patchNames:
zoneNames (patchNames);
Now cellZones are handled directly by the applications and the new
cellZone::topoChange function so that any cell can now be in any number of
zones, significantly increasing the flexibility and usefulness of cellZones.
The same rationalisation and generalisation will be applied to faceZones in the
future.
Now pointZones are handled directly by the applications and the new
pointZone::topoChange function so that any point can now be in any number of
zones, significantly increasing the flexibility and usefulness of pointZones.
The same rationalisation and generalisation will be applied to cellZones and
faceZones in the future.
The surface mesh setPoints function resets the points without caching the old
points or swept areas so is the equivalent of the polyMesh::setPoints rather
than movePoints.
This utility is superseded by the much more general transformPoints. A
rotation between vectors (0 1 0) and (0.707107 0.707107 0), and a
corresponding transformation of all vector and tensor fields, can be
achieved with the following call to transformPoints:
transformPoints "rotate=((0 1 0) (0.707107 0.707107 0))" -rotateFields
The concept of cell and face inflation proved unworkable in general and has been
replaced by the more flexible and robust cell-splitting combined with
conservative interpolative mapping and mesh morphing as appropriate.
The concept of cell inflation from faces or points proved unworkable in general
and has been replaced by the more flexible and robust cell-splitting combined
with conservative interpolative mapping and mesh morphing as appropriate.
Constructing the fields in patch order is logical, and preferable to
using the potentially arbitrary order in which the fields are specified
in the field dictionary. It also resolves the issue that the
construction of jump cyclics can fail if the patch fields are not
specified in the same order as the patches.
This utility is used as a pre-processing step for the multiValveEngine
fvMeshMover and provides two options:
-cylinderHead to generate the pointZone within the cylinder head
-pistonBowl to generate the pointZone within the piston bowl
The updated tutorials/XiFluid/kivaTest case demonstrates the application of this
utility.
Either single entries renamed using the -entry option with -rename:
-entry <entryName> -rename <newName>
or a list of entries can be renamed using the -rename <newNames> option:
-rename "<entryName0>=<newName0>, <entryName1>=<newName1>..."
Zones are now completely dynamic, i.e. the number of zones of each type can
change during the run, e.g. by run-time mesh-to-mesh mapping onto meshes with
different zones used to control mesh motion. This means that the index of each
zone may change during the run and so it better that the zones do not cache
their own index but it is looked-up from the zone list using findIndex when
required.
A new nonConformalMappedWall patch type has been added which can couple
between different regions of a multi-region simulation. This patch type
uses the same intersection algorithm as the nonConformalCyclic patch,
which is used for coupling sections of a mesh within the same region.
The nonConformalMappedWall provides some advantages over the existing
mappedWall patches:
- The connection it creates is not interpolative. It creates a pair of
coupled finite-volume faces wherever two opposing faces overlap.
There is therefore no interpolation error associated with mapping
values across the coupling.
- Faces (or parts of faces) which do not overlap are not normalised
away by an interpolation or averaging process. Instead, they are
assigned an alternative boundary condition; e.g., an external
constraint, or even another non-conformal cyclic or mapped wall.
This makes the system able to construct partially-overlapping
couplings.
- The direct non-interpolative transfer of values between the patches
makes the method equivalent to a conformal coupling. Properties of
the solution algorithm, such as conservation and boundedness, are
retained regardless of the non-conformance of the boundary meshes.
- All constructed finite volume faces have accurate centre points.
This makes the method second order accurate in space.
Usage:
Non-conformal mapped wall couplings are constructed as the last stage of
a multi-region meshing process. First, a multi-region mesh is
constructed in one of the usual ways, but with the boundaries specified
as standard non-coupled walls instead of a special mapped type. Then,
createNonConformalCouples is called to construct non-conformal mapped
patches that couple overlapping parts of these non-coupled walls. This
process is very similar to the construction of non-conformal cyclics.
createNonConformalCouples requires a
system/createNonConformalCouplesDict in order to construct non-conformal
mapped walls. Each coupling is specified in its own sub-dictionary, and
a "regions" entry is used to specify the pair of regions that the
non-conformal mapped wall will couple. Non-conformal cyclics can also be
created using the same dictionary, and will be assumed if the two
specified regions are the same, or if a single "region" entry is
specified. For example:
// Do not modify the fields
fields no;
// List of non-conformal couplings
nonConformalCouples
{
// Non-conformal cyclic interface. Only one region is specified.
fluidFluid
{
region fluid;
originalPatches (nonCoupleRotating nonCoupleStationary);
}
// Non-conformal mapped wall interface. Two different regions
// have been specified.
fluidSolid
{
regions (fluid solid);
originalPatches (nonCoupleRotating nonCoupleStationary);
}
}
After this step, a case should execute with foamMultiRun and decompose
and reconstruct and post-process normally.
One additional restriction for parallelised workflows is that
decomposition and reconstruction must be done with the -allRegions
option, so that the both sides of the coupling are available to the
decomposition/reconstruction algorithm.
Tutorials:
Two tutorials have been added to demonstrate use of this new
functionality:
- The multiRegion/CHT/misalignedDuct case provides a simple visual
confirmation that the patches are working (the exposed corners of
the solid will be hot if the non-conformal mapped walls are active),
and it demonstrates createNonConformalCouples's ability to add
boundary conditions to existing fields.
- The multiRegion/CHT/notchedRoller case demonstrates use of
non-conformal mapped walls with a moving mesh, and also provides an
example of parallelised usage.
Notes for Developers:
A coupled boundary condition now uses a new class,
mappedFvPatchBaseBase, in order to perform a transfer of values to or
from the neighbouring patch. For example:
// Cast the patch type to it's underlying mapping engine
const mappedFvPatchBaseBase& mapper =
mappedFvPatchBaseBase::getMap(patch());
// Lookup a field on the neighbouring patch
const fvPatchScalarField& nbrTn =
mapper.nbrFvPatch().lookupPatchField<volScalarField, scalar>("T");
// Map the values to this patch
const scalarField Tn(mapper.fromNeighbour(nbrTn));
For this to work, the fvPatch should be of an appropriate mapped type
which derives from mappedFvPatchBaseBase. This mappedFvPatchBaseBase
class provides an interface to to both conformal/interpolative and
non-conformal mapping procedures. This means that a coupled boundary
condition implemented in the manner above will work with either
conformal/interpolative or non-conformal mapped patch types.
Previously, coupled boundary conditions would access a mappedPatchBase
base class of the associated polyPatch, and use that to transfer values
between the patches. This direct dependence on the polyPatch's mapping
engine meant that only conformal/interpolative fvPatch fields that
corresponded to the polyPatch's geometry could be mapped.
This provides finer control as to when the changes get constructed and
initial stitching is performed. These is needed by certain processes,
notably decomposition and reconstruction.
By default, the mesh still performs all these operations on a "normal"
read-construction. A flag has to be passed explicitly to the constructor
in order to prevent the post-construction steps.
to set the time and other case controls. This is possible and reliable now that
the functionObject specifications are in a separate functions file which is not
read.
for consistency with fvModels and fvConstraints, to simplify code and case
maintenance and to avoid the potentially complex functions entries being
unnecessarily parsed by utilities for which functionObject evaluation is
disabled.
The functions entry in controlDict is still read if the functions file is not
present for backward-compatibility, but it is advisable to migrate cases to use
the new functions file.
Description
Merges meshes without stitching.
Usage
\b mergeMeshes [OPTION]
Options:
- \par -doc
Display the documentation in browser
- \par -srcDoc
Display the source documentation in browser
- \par -help
Print the usage
- \par -case \<dir\>
Select a case directory instead of the current working directory
- \par -region \<name\>
Specify an alternative mesh region.
- \par -addRegions "'(region1 region2 ... regionN)'"
Specify list of region meshes to merge.
- \par -addCases "'(\"casePath1\" \"casePath2\" ... \"casePathN\")'"
Specify list of case meshes to merge.
- \par -addCaseRegions "'((\"casePath1\" region1) (\"casePath2\" region2)"
Specify list of case region meshes to merge.
The mergePatchPairs functionality in blockMesh also now uses patchIntersection.
The new mergePatchPairs and patchIntersection replaces the old, fragile and
practically unusable polyTopoChanger::slidingInterface functionality the removal
of which has allowed the deletion of a lot of other ancient and otherwise unused
clutter including polyTopoChanger, polyMeshModifier, polyTopoChange::setAction
and associated addObject/*, modifyObject/* and removeObject/*. This
rationalisation paves the way for the completion of the update of zone handling
allowing mesh points, faces and cells to exist in multiple zones which is
currently not supported with mesh topology change.
Application
stitchMesh
Description
Utility to stitch or conform pairs of patches,
converting the patch faces either into internal faces
or conformal faces or another patch.
Usage
\b stitchMesh (\<list of patch pairs\>)
E.g. to stitch patches \c top1 to \c top2 and \c bottom1 to \c bottom2
stitchMesh "((top1 top2) (bottom1 bottom2))"
Options:
- \par -overwrite \n
Replace the old mesh with the new one, rather than writing the new one
into a separate time directory
- \par -region \<name\>
Specify an alternative mesh region.
- \par -fields
Update vol and point fields
- \par -tol
Merge tolerance relative to local edge length (default 1e-4)
See also
Foam::mergePatchPairs
Omega lower limit bounding is now based on a maximum turbulence viscosity nut
rather than a minimum omega value which improves stability and robustness of
the k-omega models in case of numerical boundedness problems.
The maximum nut value is calculated by multiplying the laminar viscosity by
nutMaxCoeff which defaults to 1e5 but can be set by the user in the
momentumTransport dictionary.
