CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Meshing & Mesh Conversion

[Other] Offset warning

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   November 25, 2009, 10:35
Default Offset warning
  #1
New Member
 
Alexander K.
Join Date: Mar 2009
Posts: 3
Rep Power: 17
Mercato is on a distinguished road
Hi Foamers,
I have create tube in tube mesh for heat exchanger with setSet. But during chtMultiRegionFoam calculation appear warnig:
Quote:
--> FOAM Warning :
From function directMappedPatchBase::calcMapping() const
in file directMapped/directMappedPolyPatch/directMappedPatchBase.C at line 451
The actual cell/face centres picked up using offset (0 0 0) are not
on a single plane. This might give numerical problems.
At patchface (-0.005366228 6.12 0.006246755) the sampled cell/face (-0.005366229 6.12 0.006246755)
is not on a plane 3.929719e-16 offset from the patch.
You might want to shift your plane offset. Set the debug flag to get a dump of sampled cells.
I guess that this warning gives nonreliable results.
Please, help to fix it up.

blockMeshDict.gz
makeCellSets.setSet.gz
Mercato is offline   Reply With Quote

Old   November 27, 2009, 07:06
Default
  #2
Member
 
Join Date: Sep 2009
Posts: 45
Rep Power: 16
AirS is on a distinguished road
Hi Mercato,
just to tell you that I've got the same error as you... That occurs when I run renumberMesh.
Moreover, how can we do what we are asked for:

"Set the debug flag to get a dump of sampled cells" ?

If you have already solved the problem, I'd appreciate your help.
Thanks.
AirS is offline   Reply With Quote

Old   November 29, 2009, 12:24
Default
  #3
New Member
 
Join Date: May 2009
Posts: 7
Rep Power: 16
dakos is on a distinguished road
Hi Mercato and AirS,

I have the same problem using a mesh I have generated with snappyhexmesh.
The problem, in my case, is in the boundary where some faces are wrong (but i don't know how i can correct them!).

Ciao
Attached Images
File Type: jpg boundary.jpg (100.2 KB, 29 views)
dakos is offline   Reply With Quote

Old   November 30, 2009, 06:15
Default
  #4
Member
 
Join Date: Sep 2009
Posts: 45
Rep Power: 16
AirS is on a distinguished road
Can anyone give me some suggestions about how to set the debug flag to get a dump of sampled cells ?I give you my inputs in constant/polyMesh/boundary :

{
type directMappedPatch;
nFaces 2291;
startFace 1200381;
sampleMode nearestCell;
sampleRegion region0;
samplePatch none;
offset ( 0.766 0 0 ); // Which is the keyword needed here ??
}

Any suggestions are welcome,
Thank you!
AirS is offline   Reply With Quote

Old   December 1, 2009, 07:27
Default
  #5
Member
 
Join Date: Sep 2009
Posts: 45
Rep Power: 16
AirS is on a distinguished road
I've finally partly solved my problem.
I add the keyword directMappedPatchBase in the controlDict (OpenFOAM-1.6/etc) followed by 1 (Debug switches). So that I can see the suggestions and another file is created: INLET_directMapped.obj. My problem is that I don't understand what it's inside the first lines being like so:

v -1 -0.08115735 0.112
v -0.2315849597 -0.08110849465 0.1120022489
l 1 2
v -1 -0.08115735 0.13
v -0.231585471 -0.08110835716 0.1299997623
l 3 4

Thanks a lot !
AirS is offline   Reply With Quote

Old   December 2, 2009, 06:35
Default
  #6
Member
 
Join Date: Sep 2009
Posts: 45
Rep Power: 16
AirS is on a distinguished road
Hi,
When I run decomposePar or renumberMesh I've got this warning:

--> FOAM Warning :
From function directMappedPatchBase::calcMapping() const
in file directMapped/directMappedPolyPatch/directMappedPatchBase.C at line 451
The actual cell/face centres picked up using offset (2 0 0) are not
on a single plane. This might give numerical problems.
At patchface (-1 -0.0811574 0.112) the sampled cell/face (1.00878 -0.0811143 0.111998)
is not on a plane 2.00502 offset from the patch.
You might want to shift your plane offset. Set the debug flag to get a dump of sampled cells.


Since it's just a warning I tried to run pisoFoam to see what happened, and it worked well. My simulation being done, I used reconstructPar and unfortunately I've got the same error. I can't understand how that can be possible actually since everything worked fine with the directMappedPatch boundary during the simulation.
Does anybody have an idea of what I could try to sort this issue out ?

Thanks !
AirS is offline   Reply With Quote

Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Caffa 3D code Waliur Rahman Main CFD Forum 0 May 29, 2018 00:53
[swak4Foam] installation problem with version 0.2.3 Claudio87 OpenFOAM Community Contributions 9 May 8, 2013 10:20
latest OpenFOAM-1.6.x from git failed to compile phsieh2005 OpenFOAM Bugs 25 February 9, 2010 04:37
Compilation errors in ThirdPartymallochoard feng_w OpenFOAM Installation 1 January 25, 2009 06:59
[blockMesh] Axisymmetrical mesh Rasmus Gjesing (Gjesing) OpenFOAM Meshing & Mesh Conversion 10 April 2, 2007 14:00


All times are GMT -4. The time now is 02:06.