122 lines
3.8 KiB
Plaintext
122 lines
3.8 KiB
Plaintext
Short overview of the changes to have cyclics split into two halves.
|
|
|
|
Cyclics
|
|
-------
|
|
The two cyclic halves are now split like processor patches. There should be no
|
|
difference in running.
|
|
|
|
Advantages:
|
|
- decomposed cyclics can now be handled properly. It just needs to preserve
|
|
the cyclic patch it originates from.
|
|
- We can now construct a table of global transformations and handle
|
|
points/edges/cells with transformations.
|
|
- face ordering after topological changes becomes much easier since we
|
|
now preserve what half the face comes from.
|
|
- cyclic handling becomes more consistent with processor handling and can
|
|
quite often be handled in the same condition.
|
|
- transformation tensors now become single entry.
|
|
|
|
The disadvantages:
|
|
- a patch-wise loop now might need to store data to go to the neighbour half
|
|
since it is no longer handled in a single patch.
|
|
- decomposed cyclics now require overlapping communications so will
|
|
only work in non-blocking mode. Hence the underlying message passing library
|
|
will require overlapping communications with message tags.
|
|
- it is quite a code-change and there might be some oversights.
|
|
- once converted (see foamUpgradeCyclics below) cases are not backwards
|
|
compatible with previous versions.
|
|
|
|
|
|
blockMesh
|
|
---------
|
|
blockMeshDict now allows patch definition using the construct-from-dictionary
|
|
constructor. This helps defining patches that require additional input e.g.
|
|
directMapped and now cyclic:
|
|
|
|
boundary
|
|
(
|
|
sides2_half0
|
|
{
|
|
type cyclic;
|
|
neighbourPatch sides2_half1;
|
|
faces ((2 4 5 3));
|
|
}
|
|
|
|
The syntax is - like the polyMesh/boundary file - a list of dictionaries with
|
|
one additional entry 'faces' for the block faces. Above shows the new
|
|
required entry 'neighbourPatch' for cyclic.
|
|
|
|
blockMesh still reads the old format. For a cyclic it will automatically
|
|
introduce two patches for the halves, with names xxx_half0 and xxx_half1.
|
|
|
|
|
|
foamUpgradeCyclics
|
|
------------------
|
|
This is a tool which reads the polyMesh/boundary file and any vol/surface/point
|
|
fields and converts them.
|
|
It will check if anything needs to be converted, backup the current file to .old
|
|
and split any cyclic patchFields into two entries.
|
|
|
|
|
|
decomposePar
|
|
------------
|
|
Decomposes cyclics into processorCyclic:
|
|
|
|
procBoundary0to1throughsides1_half0
|
|
{
|
|
type processorCyclic;
|
|
nFaces 1000;
|
|
startFace 91350;
|
|
myProcNo 0;
|
|
neighbProcNo 1;
|
|
referPatch sides1_half0;
|
|
}
|
|
|
|
They have an additional 'referPatch' entry which gives the (cyclic) patch
|
|
to use for any transformation.
|
|
|
|
|
|
Details
|
|
-------
|
|
- the cyclic patch dictionary has an entry neighbourPatch. The
|
|
patch has new member functions:
|
|
|
|
//- Get neighbouring patchID
|
|
label neighbPatchID() const
|
|
|
|
//- Get neighbouring patch
|
|
const cyclicPolyPatch& neighbPatch()
|
|
|
|
//- Am I the owner half
|
|
bool owner()
|
|
|
|
The cyclic still has forward() and reverse() transformations (with
|
|
the reverse() equal to the neighbPatch().forward()).
|
|
|
|
There is no transformLocalFace anymore - the ordering is the same for
|
|
both halves.
|
|
|
|
|
|
- 'pure' processor patches now are always coincident - they (should) have no
|
|
transformation. As said above cyclics are decomposed into a derived
|
|
type 'processorCyclic'.
|
|
|
|
|
|
- processor patches use overlapping communication using a different message
|
|
tag. This maps straight through into the MPI message tag.
|
|
See processorCyclicPolyPatch::tag(). This needs to be calculated the
|
|
same on both sides so is calculated as
|
|
Pstream::nProcs()*max(myProcNo, neighbProcNo)
|
|
+ min(myProcNo, neighbProcNo)
|
|
which is
|
|
- unique
|
|
- commutative
|
|
- does not interfere with the default tag (= 1)
|
|
|
|
|
|
- when constructing a GeometricField from a dictionary it will explicitly
|
|
check for non-existing entries for cyclic patches and exit with an error message
|
|
warning to run foamUpgradeCyclics.
|
|
|
|
|