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hansel July 3, 2009 13:08

Uncovered faces found ????
I'm using OpenFOAM-1.5-dev Ubuntu 9.04 64 bit.

I'm attempting to set up a rotating mesh, with a cylinder inside a block with a hole, just a little larger than the cylinder. (the cylinder is about 2M across and the gap is 0.5mm) See picture at end.

When I run it, I get this error:
From function void GGIInterpolation<MasterPatch, SlavePatch>::rescaleWeightingFactors() const
in file /storage/software/OpenFOAM/OpenFOAM-1.5-dev/src/OpenFOAM/lnInclude/GGIInterpolationWeights.C at line 533
Uncovered faces found. On master: 98 on slave: 504
Largest slave weighting factor correction : 0.4458582 average: 0.04798944
Largest master weighting factor correction: 1 average: 0.2857143

Selecting incompressible transport model Newtonian
Selecting RAS turbulence model kEpsilon
Cmu 0.09;
C1 1.44;
C2 1.92;
alphaEps 0.76923;

Reading field rAU if present

Starting time loop

Courant Number mean: 0.002633346 max: 0.02407465 velocity magnitude: 1.107188
Time = 2.001

Segmentation fault
What is an uncovered face? Does it have to do with the two meshes not lining up perfectly?

I tried it with several different programs:
turbDyMFoam - error and crash
icoDyMFoam - error and crash
IcoFoam error message, doesn't crash, good results.
PotentialFoam error message, no crash, strange results. (velocity changes through ggi interface, like light through a lens.)
traceback on the crash is:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7f7dd8b7d700 (LWP 6293)]
0x00007f7dd8768124 in Foam::mixerGgiFvMesh::calcMovingMasks () from /storage/software/OpenFOAM/OpenFOAM-1.5-dev/lib/linux64GccDPOpt/
Current language: auto; currently asm
(gdb) where
#0 0x00007f7dd8768124 in Foam::mixerGgiFvMesh::calcMovingMasks () from /storage/software/OpenFOAM/OpenFOAM-1.5-dev/lib/linux64GccDPOpt/
#1 0x00007f7dd87690ad in Foam::mixerGgiFvMesh::movingPointsMask () from /storage/software/OpenFOAM/OpenFOAM-1.5-dev/lib/linux64GccDPOpt/
#2 0x00007f7dd87690eb in Foam::mixerGgiFvMesh::update () from /storage/software/OpenFOAM/OpenFOAM-1.5-dev/lib/linux64GccDPOpt/
#3 0x0000000000416047 in main ()
(gdb) list
1 /build/buildd/glibc-2.9/build-tree/amd64-libc/csu/crtn.S: No such file or directory.
in /build/buildd/glibc-2.9/build-tree/amd64-libc/csu/crtn.S
(gdb) Quit


hansel July 3, 2009 13:09

BTW, the GGI questions and answers are spread all over the place. I think there should be an OpenFOAM -> Meshes -> GGI / moving meshes section.

hansel July 3, 2009 23:53

Okay, I made some progress. The uncovered faces are just what it sounds like. When I made my face zones I included the top and bottom. I should have just had the mating faces. So that error is gone.

Unfortunately I'm down to just a core dump with no explanation. It's somewhere in the GGI when it's moving the mesh.

mahaputra July 4, 2009 04:41

Dear Hansel

sorry, just wondering

which meshing generator/tool you use for meshing your posted geometry? (a box with a circle inside)


hansel July 4, 2009 11:25


Originally Posted by mahaputra (Post 221448)
Dear Hansel

sorry, just wondering

which meshing generator/tool you use for meshing your posted geometry? (a box with a circle inside)


I used blockMesh for the basic cylinder and block. Once I get this working, I plan to carve the test item out of the cylindar using snappyHexMesh.

By the way, if I can ever make this work, I'll write up step by step instructions on how I did it to make it easier for everyone else.

Hasselhoff July 10, 2009 14:05

Hi everybody:)

That's right- it's hard to get ggi- related information. It would be nice if there was some faq somewhere;) GGI worked out real nice for me for nonrotatin and overlapping interfaces- If someone needs information about that, feel free to ask;)
But if I add some nonoverlapping Interfaces, the whole thing doesn't work quite long. I guess the difficulty is how to declare the bridgeOverlap.
The Mesh was generated in Gambit, the Solver is rhoSimpleFoam. The Pictures (interfaces) show the top of a turbomachinery component, walls are periodic.. The flux is supposed to go from the inside through the Honeycomb area.
The honeycomb structures are meshed tri, block (inside) is meshed hex.
My boundary file looks like the following:

type ggi;
nFaces 221;
startFace 1476442;
shadowPatch Step;
zone zone_ HoneyComb_Step;
bridgeOverlap true;
type ggi;
nFaces 40;
startFace 1476663;
shadowPatch HoneyComb_Step;
zone zone_ Step;
bridgeOverlap true;
type ggi;
nFaces 2880;
startFace 1476703;
shadowPatch Level_2;
zone HoneyComb_Level_2;
bridgeOverlap true;
type ggi;
nFaces 1289;
startFace 1482568;
shadowPatch HoneyComb_Level_2;
zone zone_Level_2;
bridgeOverlap true;
type ggi;
nFaces 2985;
startFace 1479583;
shadowPatch Level_1;
zone zone_ HoneyComb_Level_1;
bridgeOverlap true;
type ggi;
nFaces 1064;
startFace 1483857;
shadowPatch HoneyComb_Level_1;
zone zone_Level_1;
bridgeOverlap true;
is there a mistake in my boundary- file? Thank you for answering!

best, Mitch

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