BUG: Fixes bug in plicRDF interface reconstruction across cyclic boundaries (fixes #3279)

Description:
The plicRDF interface reconstruction scheme calculates a reconstructed distance
function (RDF) in all interface cells and their point neighbours.
In point neighbours to interface cells, the RDF is calculated as a weighted
average of the distances to all adjacent interface cell centres with the weight
being the inverse distance to the cell centre.
By using the zoneDistribute class written by Henning Scheufler, the required
stencil data is communicated efficiently for stencil cells living on different
sides of one or more processor patches.
Some of the data required for the RDF reconstruction are cell centre and
interface centre positions. When a stencil extends across a cyclic patch these
positions have so far not been properly transformed in OpenFOAM. This issue is
fixed by the current contribution.
The fix is done by modifying the zoneDistribute class to hold the required
information about zone cells adjacent to cyclic patches. Positions are then
communicated with a new getPosition function which replaces getValue for
position data in the reconstructedDistanceFunction and plicRDF classes.
The implementation does not change the behaviour for cells not on
a cyclic patch and should have insignificant effect on efficiency for these.
The implementation can probably be optimised in terms of efficiency for zone
cells on cyclic patches, but we note that there are generally only very few of
these (interface cells and their point neighbours on cyclic patches) and so
the potential for speedup is expected to be limited.

Current limitations:

- In parallel, the user must constrain the decomposition to preserve cyclic
patches on the same processor, for the implementation to work properly.
  - See an example here: tutorials/discInConstantFlowCyclicBCs/system/decomposeParDict
- In the case of parallel rotational cyclics that are split by the decomposition
the current bugfix does not work and therefore throws an error. This is ongoing
work and should be reported and fixed by a future patch.

For further details, please see the modified files and the comments therein:
- $FOAM_SRC/finiteVolume/fvMesh/zoneDistribute/zoneDistribute.H
- $FOAM_SRC/finiteVolume/fvMesh/zoneDistribute/zoneDistribute.C
- $FOAM_SRC/finiteVolume/fvMesh/zoneDistribute/zoneDistributeI.H
- $FOAM_SRC/transportModels/geometricVoF/reconstructedDistanceFunction/reconstructedDistanceFunction.C
- $FOAM_SRC/src/transportModels/geometricVoF/reconstructionSchemes/plicSchemes/plicRDF/plicRDF.C

Co-authored-by: David Müller <> KIT
Co-authored-by: Konstantinos Missios <> Roskilde University
Co-authored-by: Johan Roenby <> Roskilde University and STROMNING

tutorials/multiphase/interIsoFoam/discInConstantFlowCyclicBCs/Allclean

@@ -5,4 +5,6 @@ cd "${0%/*}" || exit                                # Run from this directory
 
 cleanCase0
 
+rm -f Phase1
+
 #------------------------------------------------------------------------------

tutorials/multiphase/interIsoFoam/discInConstantFlowCyclicBCs/Allrun

@@ -5,10 +5,20 @@ cd "${0%/*}" || exit                                # Run from this directory
 
 restore0Dir
 
+touch case.foam
+
 runApplication blockMesh
 
 runApplication setAlphaField
 
-runApplication $(getApplication)
+runApplication decomposePar
+
+runParallel $(getApplication)
+
+grep "Phase-1" log.$(getApplication) | cut -d' ' -f5 > Phase1
+
+echo "Volume conservation:"
+echo "Initial Phase-1: " $(head -1 Phase1)
+echo "Final Phase-1  : " $(tail -1 Phase1)
 
 #------------------------------------------------------------------------------

tutorials/multiphase/interIsoFoam/discInConstantFlowCyclicBCs/system/controlDict

@@ -35,7 +35,7 @@ purgeWrite      0;
 
 writeFormat     ascii;
 
-writePrecision  6;
+writePrecision  12;
 
 writeCompression off;
 

tutorials/multiphase/interIsoFoam/discInConstantFlowCyclicBCs/system/decomposeParDict

@@ -24,5 +24,13 @@ coeffs
     n   ( 2 1 2 );
 }
 
+constraints
+{
+    preservePatches
+    {
+        type            preservePatches;
+        patches         (left right top bottom);
+    }
+}
 
 // ************************************************************************* //

tutorials/multiphase/interIsoFoam/discInConstantFlowCyclicBCs/system/fvSolution

@@ -22,10 +22,10 @@ solvers
     {
         isoFaceTol      1e-6;
         surfCellTol     1e-6;
-        snapTol         1e-10;
+        snapTol         0;
         nAlphaBounds    3;
-        clip            true;
-        reconstructionScheme isoAlpha; // isoAlpha
+        clip            false;
+        reconstructionScheme plicRDF;
 
         nAlphaSubCycles 1;
         cAlpha          1; // Read but not used by interIsoFoam