[Other] Grid quatlity for particle tracking

yhoarau · June 12, 2015, 06:07

Hi,

I have to perform a particle tracking in a blood micro vessel network. I have an stl file for the geometry and I build the grid with snappyHexmesh. My grid is OK for the flow but not for the particles :
--> FOAM FATAL ERROR:
No base point for face 1854708, 4(894291 917963 919857 916949), produces a decomposition that has a minimum volume greater than tolerance.

I tried many unsuccessful combination in snappyHexMeshDict which I join here.
Can someone tell me which parameters I have to modify to generate a nice grid?

Thanks

Yannick

Mojtaba.a · June 16, 2016, 07:36

Quote:

Originally Posted by yhoarau

Hi,

I have to perform a particle tracking in a blood micro vessel network. I have an stl file for the geometry and I build the grid with snappyHexmesh. My grid is OK for the flow but not for the particles :
--> FOAM FATAL ERROR:
No base point for face 1854708, 4(894291 917963 919857 916949), produces a decomposition that has a minimum volume greater than tolerance.

I tried many unsuccessful combination in snappyHexMeshDict which I join here.
Can someone tell me which parameters I have to modify to generate a nice grid?

Thanks

Yannick

Have you find anything about this? Its really a strange and annoying error.
Do you know how to change the tolerance mentioned in the error?

yhoarau · June 16, 2016, 08:11

Hi

No i was not able to fix this issue, I tried many grid generation but so faar nothing is working!

Mojtaba.a · June 16, 2016, 08:42

Quote:

Originally Posted by yhoarau

Hi

No i was not able to fix this issue, I tried many grid generation but so faar nothing is working!

Ok I made a similar mesh in an another software (ANSYS ICEM CFD) and it worked just fine.
I guess SHM has some problems and produces low quality tet meshes.

yhoarau · June 16, 2016, 08:46

YEP if you have ICEM then te-meshes are OK.
Hexa grid is much more complicated.

Chrisi1984 · June 19, 2016, 08:05

Hello,

regarding this topic I recommend you to read the following thread:
http://www.cfd-online.com/Forums/ope...mposition.html

Kind regards
Chrisi

yhoarau · June 19, 2016, 08:26

Hi

Thanks Chrisi, this post gives idea on why the grid is not OK but unfortunately not how to fix the problem.

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June 16, 2016, 08:11		#3
yhoarau New Member Hoarau Yannick Join Date: Mar 2009 Posts: 24 Rep Power: 17	Hi No i was not able to fix this issue, I tried many grid generation but so faar nothing is working!

June 16, 2016, 08:46		#5
yhoarau New Member Hoarau Yannick Join Date: Mar 2009 Posts: 24 Rep Power: 17	YEP if you have ICEM then te-meshes are OK. Hexa grid is much more complicated.

June 19, 2016, 08:05		#6
Chrisi1984 Senior Member Join Date: Jan 2010 Location: Stuttgart Posts: 150 Rep Power: 16	Hello, regarding this topic I recommend you to read the following thread: http://www.cfd-online.com/Forums/ope...mposition.html Kind regards Chrisi

June 19, 2016, 08:26		#7
yhoarau New Member Hoarau Yannick Join Date: Mar 2009 Posts: 24 Rep Power: 17	Hi Thanks Chrisi, this post gives idea on why the grid is not OK but unfortunately not how to fix the problem.