[blockMesh] How can I connect 2 blocks with a different grading?

Ghash · November 15, 2009, 15:46

Hi

In my mesh, I need to connect blocks where the cell-faces don't exactly fit. Sometimes the number of cells is different, sometimes the grading. Is there a way to do this? I was trying around for some time now, but didn't find a way.

Perhaps someone can help me?

Regards
Ghash

johannesk · November 16, 2009, 03:21

Hi Gash,

have a look at the general grid interface (GGI) in OpenFOAM-1.5-dev, which provides a way to interpolate between non-matching cell-faces/patches. The 1.5-dev version also has a tutorial case: icoDyMFoam/mixerGgi

cheers,
Johannes

hjasak · November 18, 2009, 05:09

A sliding interface (called mergedPatchPairs in blockMesh) should also do the job for you.

Good luck,

Hrv

alank · June 29, 2010, 13:25

Is there a tutorial for version 1.6 that shows this? I'm having a similar problem with a wedge geometry; I have two blocks with different grid spacing that I want to merge, but I keep getting errors. If I try face matching as described in the User Guide, I get errors that there is an inconsistent number of faces between the two blocks. If I try tface merging by defining patches on the interface between the two blocks and putting the faces in the mergePatchPairs list at the end of the blockMeshDict file, I get errors that this, followed by a large amount of additional text:

Trying to specify a boundary face 4(3 4 5 3) on the face on cell 0 which is either an internal face or already belongs to some other patch.

gned · September 14, 2016, 10:27

Alan,
probably your error was about that :

When defining a face of a patch, the vertices of the neighbor blocks or patches must not have the same vertices number, you have to create double vertices, meaning same points but other vertices number.

November 15, 2009, 15:46	How can I connect 2 blocks with a different grading?	#1
Ghash New Member Steffen Goertz Join Date: Jul 2009 Posts: 4 Rep Power: 16	Hi In my mesh, I need to connect blocks where the cell-faces don't exactly fit. Sometimes the number of cells is different, sometimes the grading. Is there a way to do this? I was trying around for some time now, but didn't find a way. Perhaps someone can help me? Regards Ghash

November 16, 2009, 03:21	Ggi	#2
johannesk New Member Johannes Kneer Join Date: Mar 2009 Location: Germany, Karlsruhe Posts: 13 Rep Power: 17	Hi Gash, have a look at the general grid interface (GGI) in OpenFOAM-1.5-dev, which provides a way to interpolate between non-matching cell-faces/patches. The 1.5-dev version also has a tutorial case: icoDyMFoam/mixerGgi cheers, Johannes

November 18, 2009, 05:09		#3
hjasak Senior Member Hrvoje Jasak Join Date: Mar 2009 Location: London, England Posts: 1,905 Rep Power: 33	A sliding interface (called mergedPatchPairs in blockMesh) should also do the job for you. Good luck, Hrv __________________ Hrvoje Jasak Providing commercial FOAM/OpenFOAM and CFD Consulting: http://wikki.co.uk

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June 29, 2010, 13:25		#4
alank New Member Alan Kastengren Join Date: Mar 2009 Posts: 3 Rep Power: 17	Is there a tutorial for version 1.6 that shows this? I'm having a similar problem with a wedge geometry; I have two blocks with different grid spacing that I want to merge, but I keep getting errors. If I try face matching as described in the User Guide, I get errors that there is an inconsistent number of faces between the two blocks. If I try tface merging by defining patches on the interface between the two blocks and putting the faces in the mergePatchPairs list at the end of the blockMeshDict file, I get errors that this, followed by a large amount of additional text: Trying to specify a boundary face 4(3 4 5 3) on the face on cell 0 which is either an internal face or already belongs to some other patch.

September 14, 2016, 10:27		#5
gned New Member gned Join Date: Oct 2012 Posts: 18 Rep Power: 13	Alan, probably your error was about that : When defining a face of a patch, the vertices of the neighbor blocks or patches must not have the same vertices number, you have to create double vertices, meaning same points but other vertices number.