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-   -   [snappyHexMesh] sHM and cyclicGgi (https://www.cfd-online.com/Forums/openfoam-meshing/81228-shm-cyclicggi.html)

FabOr November 8, 2010 10:08

Hi Thomas,

thanks. the result looks nice. thats exactly what i´ve want. i hope i can transfer the setting on a mesh made by shm (different number of faces on the opposite sides)...

what steps did you take?
1) blockMesh
2) faceSet
3) setsToZones -noFlipMap
4) change boundary-file

best regards

anger November 8, 2010 15:48

Quote:

Originally Posted by FabOr (Post 282628)
Hi Thomas,

thanks. the result looks nice. thats exactly what i´ve want. i hope i can transfer the setting on a mesh made by shm (different number of faces on the opposite sides)...

what steps did you take?
1) blockMesh
2) faceSet
3) setsToZones -noFlipMap
4) change boundary-file

best regards


Hello FabOr,

for the second step, I used setSet -batch system/setSetBatch (just for the sake of completeness, faceSet should also work (I think ;)) ), all other steps are ok.

Best regards,
-Thomas

FabOr November 9, 2010 03:19

Hi Thomas,

it works also with shm-meshes:)

Thank you very much!

Best regards

hardykalyan November 10, 2010 10:20

Hi Thomas,

Thank you very much for the case file and it helped me to understand ggi well.

Can you suggest me an idea of using the non-matching grids(think-cyclicGgi) and a rotating solid(ggi) together in the same case?

anger November 15, 2010 15:36

further explanation needed
 
Quote:

Originally Posted by hardykalyan (Post 282934)
Hi Thomas,

Thank you very much for the case file and it helped me to understand ggi well.

Can you suggest me an idea of using the non-matching grids(think-cyclicGgi) and a rotating solid(ggi) together in the same case?

Hello hardykalyan,

sorry, I don't understand what you mean, can you explain it furhter and/or supply a sketch?

Best regards,
-Thomas

claco February 25, 2011 09:17

Quote:

Originally Posted by anger (Post 281623)
Hi FabOr,

The link I mentioned above is
http://www.tfd.chalmers.se/~hani/kurser/OS_CFD/case_study_2010_OP.pdf
where you can find informations on setting up a ggi boundary for either cyclic or translational cases.
I think ggi (not cyclicGgi!) will work for your case. You could start by taking the mesh of a tutorial case (like channel395), change it to your needs and then introduce the ggi instead of the standard cyclic bc to get an idea of the correct setup. Be aware that ggi only works in 1.5-dev.

Best regards,
-Thomas


Dear Thomas,

I am using OF 1.5-dev (the last version released). I am simulating a blade of a radial pump.

I am using cyclicGgi patch, with the bridgeOverlap=false option. But when I run the MRFSimpleFoam solver, the message "Found uncovered faces for GGI interface Per1/Per2 while the bridgeOverlap option is not set in the boundary file." appears.

I personally think that i would have to set this option true, because the cyclic patches do not overlap with themselves.

What can You kindly suggest me to this purpose?

Best regards,

Claudio



However, when I run

anger February 26, 2011 05:36

Hi Claudio,

meanwhile there is OF-1.6-ext which is also capable of GGI interpolation and is the successor of 1.5-dev, so the things stated above are a little bit outdated.
Regarding your problem, if the patches do not geometrically match, then set bridgeOverlap to true. However, for a radial pump, I'm not sure why they shouldn't do so. If you created your mesh with sHM, than there might be problems because sHM edges are not following strictly the stl geometry, and if this was the case, you'd have to be clear about the effects of setting bridgeOverlap to true to get the simulation running.

Regards,
-Thomas

aqua February 8, 2012 14:58

Quote:

Originally Posted by anger (Post 281245)
Hi FabOr,

if the second file was your actual one, following things are strange:
- there is only one cyclicGgi entry; there should be two (for example "cyclicY")
- not all subentries are filled in; you have to define the correct shadow patch (if the above was correct, the shadow patch entry in "cyclicX" should be "cyclicY")
- your mesh has to have the corresponding face zones which you also have to define for example via faceSet
- take care of the rotation angle; fill in the correct value for your case.

I'll have a look whether I can find a very simple test case to demonstrate the setup. Meanwhile, you could search the net (I remember that I derived my setup from a presentation of a member of the turbomachinery SIG, but I don't remember the name...)

Regards,
-Thomas

Hello Thomas,
Does rotationAngle mean the angle between the two patches which are setted as cyclicGgi? How to decide the angle is positive or negative? Because in the 1.6-ext tutorial, the case "turboPassangeRotating", the rotationAngle is 30 degree for one patch and -30 degree for the couple patch..I don't know why...

Thank you so much!

Aqua

BSengupta October 29, 2019 00:48

I see it's quite a past post, but still felt relevant for my problem.


I am trying to run overlapGgi and getting the error as:
--> FOAM FATAL ERROR:
Found uncovered faces for GGI interface innercylinder/outercylinder
This is an unrecoverable error. Aborting.


boundary
blade_1
{
type wall;
nFaces 46561;
startFace 5183059;
}
blade_2
{
type wall;
nFaces 39728;
startFace 5229620;
}
innercylinder
{
type overlapGgi;
nFaces 41878;
startFace 5269348;
rotationAxis (0 0 1);
nCopies 30;
shadowPatch outercylinder;
zone innercylinder_faces;
}
outercylinder
{
type overlapGgi;
nFaces 41880;
startFace 5326982;
rotationAxis (0 0 1);
nCopies 30;
shadowPatch innercylinder;
zone outercylinder_faces;
}
farfield
{
type patch;
nFaces 15756;
startFace 5311226;
}


setBatch


faceSet innercylinder_faces new patchToFace innercylinder
faceSet outercylinder_faces new patchToFace outercylinder
cellSet rotor new cellToCell cellRegion0
quit




dynamicMeshDict

dynamicFvMeshLib "libtopoChangerFvMesh.so";
dynamicFvMesh turboFvMesh;//mixerGgiFvMesh;

turboFvMeshCoeffs//mixerGgiFvMeshCoeffs
{
coordinateSystem
{
type cylindrical;
origin (0 0 0);
axis (0 0 1);
direction (1 0 0);
}

rpm
{
cellRegion0 360;
cellRegion1 0.0;
}

slider
{
insidecylinder_faces 360;
}

}


MRFZones
cellRegion0//rotor
{
nonRotatingPatches (farfield);

origin origin [0 1 0 0 0 0 0] (0 0 0);
axis axis [0 0 0 0 0 0 0] (0 0 1);
omega omega [0 0 -1 0 0 0 0] 360;
}




Command
regionCellSets
setSet -batch setBatch
setsToZones -noFlipMap
solverName


Can any one tell me how to resolve this error.


The figure shows blade1, blade2 and innercylinder.



Thanks a lot.


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