[Aadhavan]

Hi Fomers,
I am facing a strange problem, I am using OF-2.0.1.
I have done meshing in Gambit and exported mesh as .msh file (domain has cyclic BC ).
I am trying to convert the mesh in to OF format, for that i followed the the steps as follows:

1) fluent3DMeshToFoam - its giving small error and converting the mesh (I am not sure about the error)

fluent3DMeshToFoam


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Dimension of grid: 3
Number of points: 3261384
PointGroup: 1 start: 0 end: 3261383. Reading points...done.
Number of faces: 9496429
FaceGroup: 3 start: 0 end: 26039. Reading mixed faces...done.
FaceGroup: 4 start: 26040 end: 52079. Reading mixed faces...done.
--> FOAM Warning : Found unknown block of type: "18"
on line 3313480
FaceGroup: 5 start: 52080 end: 113583. Reading mixed faces...done.
FaceGroup: 6 start: 113584 end: 175087. Reading mixed faces...done.
--> FOAM Warning : Found unknown block of type: "18"
on line 3462534
FaceGroup: 7 start: 175088 end: 177257. Reading mixed faces...done.
FaceGroup: 8 start: 177258 end: 211977. Reading mixed faces...done.
FaceGroup: 9 start: 211978 end: 212852. Reading mixed faces...done.
FaceGroup: 10 start: 212853 end: 227552. Reading mixed faces...done.
FaceGroup: 11 start: 227553 end: 262272. Reading mixed faces...done.
FaceGroup: 12 start: 262273 end: 266247. Reading mixed faces...done.
FaceGroup: 13 start: 266248 end: 280947. Reading mixed faces...done.
FaceGroup: 14 start: 280948 end: 283117. Reading mixed faces...done.
FaceGroup: 16 start: 283118 end: 9496428. Reading mixed faces...done.
Number of cells: 3118290
CellGroup: 2 start: 0 end: 3118289 type: 1
Zone: 2 name: fluid type: fluid. Reading zone data...done.
Zone: 3 name: ILR_shadow type: shadow. Reading zone data...done.
Zone: 4 name: ILR type: periodic. Reading zone data...done.
Zone: 5 name: OLR_shadow type: shadow. Reading zone data...done.
Zone: 6 name: OLR type: periodic. Reading zone data...done.
Zone: 7 name: outlet type: pressure-outlet. Reading zone data...done.
Zone: 8 name: top2 type: wall. Reading zone data...done.
Zone: 9 name: top1 type: wall. Reading zone data...done.
Zone: 10 name: top0 type: wall. Reading zone data...done.
Zone: 11 name: center1 type: wall. Reading zone data...done.
Zone: 12 name: fan type: wall. Reading zone data...done.
Zone: 13 name: center0 type: wall. Reading zone data...done.
Zone: 14 name: inlet type: velocity-inlet. Reading zone data...done.
Zone: 16 name: default-interior type: interior. Reading zone data...done.

FINISHED LEXING

Creating patch 0 for zone: 3 name: ILR_shadow type: shadow
Adding polyPatch for unknown Fluent type shadow
Creating patch 1 for zone: 4 name: ILR type: periodic
Adding polyPatch for unknown Fluent type periodic
Creating patch 2 for zone: 5 name: OLR_shadow type: shadow
Adding polyPatch for unknown Fluent type shadow
Creating patch 3 for zone: 6 name: OLR type: periodic
Adding polyPatch for unknown Fluent type periodic
Creating patch 4 for zone: 7 name: outlet type: pressure-outlet
Creating patch 5 for zone: 8 name: top2 type: wall
Creating patch 6 for zone: 9 name: top1 type: wall
Creating patch 7 for zone: 10 name: top0 type: wall
Creating patch 8 for zone: 11 name: center1 type: wall
Creating patch 9 for zone: 12 name: fan type: wall
Creating patch 10 for zone: 13 name: center0 type: wall
Creating patch 11 for zone: 14 name: inlet type: velocity-inlet
Creating cellZone 0 name: fluid type: fluid
Creating faceZone 0 name: default-interior type: interior
faceZone from Fluent indices: 283118 to: 9496428 type: interior
patch 0 from Fluent indices: 0 to: 26039 type: shadow
patch 1 from Fluent indices: 26040 to: 52079 type: periodic
patch 2 from Fluent indices: 52080 to: 113583 type: shadow
patch 3 from Fluent indices: 113584 to: 175087 type: periodic
patch 4 from Fluent indices: 175088 to: 177257 type: pressure-outlet
patch 5 from Fluent indices: 177258 to: 211977 type: wall
patch 6 from Fluent indices: 211978 to: 212852 type: wall
patch 7 from Fluent indices: 212853 to: 227552 type: wall
patch 8 from Fluent indices: 227553 to: 262272 type: wall
patch 9 from Fluent indices: 262273 to: 266247 type: wall
patch 10 from Fluent indices: 266248 to: 280947 type: wall
patch 11 from Fluent indices: 280948 to: 283117 type: velocity-inlet

Writing mesh to "/home/cerecam/OpenFOAM/OpenFOAM-2.0.1/tutorials/incompressible/MRFSimpleFoam/meshCheck/constant/region0"

End

2) while executing the createPatch, I am facing the strange error as follows,
Create time

Reading createPatchDict.

Create polyMesh for time = 0

Adding new patch ILR0 as patch 12 from
{
type cyclic;
neighbourPatch ILR1;
transform rotational;
rotationAxis ( 1 0 0 );
rotationCentre ( 0 0 0 );
matchTolerance 0.001;
}

Adding new patch ILR1 as patch 13 from
{
type cyclic;
neighbourPatch ILR0;
transform rotational;
rotationAxis ( 1 0 0 );
rotationCentre ( 0 0 0 );
matchTolerance 0.001;
}

Adding new patch OLR0 as patch 14 from
{
type cyclic;
neighbourPatch OLR1;
transform rotational;
rotationAxis ( 1 0 0 );
rotationCentre ( 0 0 0 );
matchTolerance 0.001;
}

Adding new patch OLR1 as patch 15 from
{
type cyclic;
neighbourPatch OLR0;
transform rotational;
rotationAxis ( 1 0 0 );
rotationCentre ( 0 0 0 );
matchTolerance 0.001;
}


Moving faces from patch ILR_shadow to patch 12
Moving faces from patch ILR to patch 13
Moving faces from patch OLR_shadow to patch 14
Moving faces from patch OLR to patch 15

Doing topology modification to order faces.

Cannot find point in pts1 matching point 32 coord-0.0736604 0.0160827 0.550332) in pts0 when using tolerance 5.23475e-06
Searching started from:1195 in pts1
Compared coord-0.115922 0.0165229 0.542977) with difference to point 0.0428991
Compared coord-0.0736604 0.0160827 0.550327) with difference to point 5.27824e-06
Cannot find point in pts1 matching point 94 coord-0.0806652 0.0160937 0.550398) in pts0 when using tolerance 5.23717e-06
Searching started from:1205 in pts1
Compared coord-0.345983 0.0237373 0.435209) with difference to point 0.289345
Compared coord-0.0806652 0.0160936 0.550393) with difference to point 5.27625e-06
Cannot find point in pts1 matching point 156 coord-0.0876774 0.0161047 0.550465) in pts0 when using tolerance 5.23967e-06

--> FOAM FATAL ERROR:
face 0 area does not match neighbour by 0.118326% -- possible face ordering problem.
patch:OLR0 my area:4.88022e-05 neighbour area:4.886e-05 matching tolerance:0.001
Mesh face:9373421 fc0.0913107 -0.258775 0.180536)
Neighbour fc0.0908193 -0.0562288 0.310645)
If you are certain your matching is correct you can increase the 'matchTolerance' setting in the patch dictionary in the boundary file.
Rerun with cyclic debug flag set for more information.

From function cyclicPolyPatch::calcTransforms()
in file meshes/polyMesh/polyPatches/constraint/cyclic/cyclicPolyPatch.C at line 220.

FOAM exiting


I am able to create patches by increasing the matchTolerance 0.01

but the checkMesh failed.
CheckMesh error message:

**Error in coupled point location: 26000 faces have their 0th vertex not opposite their coupled equivalent. Average mismatch 0.00876061.
<<Writing 26000 faces with incorrectly matched 0th vertex to set coupledFaces

please help me to solve this error.


Thanks,
Aadhavan

[Aadhavan]

Hi there,
The question has been not answered yet, I found answer for one question.

" FaceGroup: 3 start: 0 end: 26039. Reading mixed faces...done.
FaceGroup: 4 start: 26040 end: 52079. Reading mixed faces...done.
--> FOAM Warning : Found unknown block of type: "18"
on line 3313480
FaceGroup: 5 start: 52080 end: 113583. Reading mixed faces...done.
FaceGroup: 6 start: 113584 end: 175087. Reading mixed faces...done.
--> FOAM Warning : Found unknown block of type: "18"
on line 3462534 "

while converting your .msh file in to OF format, if you get above message, its not an error. It is because of the other way of defined periodic condition.

But the second question is still open, so for I am not understanding it.
I have given equal number of intervals for all four edges as well I am using the mesh for my simulation.

however still I am looking for some reason, why I am getting such error message.


Thanks,
Aadhavan

[mrishi]

Hey, did you find the solution?

@admin: Sorry I know its an old post but I was very curious.