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Problem with importing a 2millions cell geometry

Submitted by Samir on August 20, 2012 - 04:19

Good day,

I tried all the tutorials of Caedium with success, I imported also small mesh from Meshing ANSYS with success.
When I try to import any mesh with more than 2M cells, Caedium becomes very slow and crashes constantly.
I tried with different cases I had, and I had always this problem.

Globally, I have this error, but the error line depends on the case I try but also vary for the same case. I respected while saving fluent case that it was in ASCII format.

Importing: FLUENT cas[e]
Error:
Failed: Import Geometry
Unexpected process exit.

--> FOAM FATAL ERROR:
Do not understand characters: +
on line 27572207

From function fluentMeshToFoam::lexer
in file fluent3DMeshToFoam.L at line 753.

FOAM exiting

Does it mean that Caedium do not support such big geometry?

Thank you for any answer you could give me.

‹ Cluster Configuration Error loading Caedium 4 on Linux ›

Case size is only limited by RAM

Submitted by symscape on August 20, 2012 - 08:11.

Caedium is fine with large cases/geometry as long as you have enough RAM in your computer. You likely need about 1 GB per 1M cells.

Please share your computer specification, i.e., CPU, RAM etc.

Which platform are you using? E.g., Windows

Things to check:

  • You are using the latest Caedium 64-bit version
  • The FLUENT case has standard elements, i.e., no arbitrary polyhedra and no hanging nodes

Are you sure this case is of the order of 2M cells? The error you quoted relates to line 27,572,207 - that might suggest a much larger case, which has implications as to whether you have enough RAM.

Please share the case so I can run some diagnostics. I suggest you use a file sharing service such as Dropbox and use our contact form to share the file's location.

Thank you for your fast

Submitted by Samir on August 20, 2012 - 08:29.

Thank you for your fast reply.

I am using WindowsServer HPC 2008 64 bits SP2 on an Intel Xeon CPU X5670 @2.93 GHZ with 48GB Ram.

I am also using the latest version of Caedium, I've checked for updates.

In the Fluent case, only standard elements are used.

The case I exported from Fluent had around 2M cells, it was the smallest case I could find to test.

I'm sorry, but I cannot share my case for confidential reasons.

Could it be the complexity of the geometry?

Thank you very much for your help.

PS: It seems to me that the problem comes from OpenFOAM, no?

Appears to be an OpenFOAM filter issue

Submitted by symscape on August 20, 2012 - 09:03.

It sounds like your computer has more than adequate resources.

The error you quoted is from the OpenFOAM FLUENT import filter, so yes that is an OpenFOAM issue.

It's unlikely that complexity is the source of the problem, unless the mesh is corrupt. Does it have multiple volumes zones? That might cause a problem, though I've never tried such a case.

Did you write out the case from FLUENT on Windows? I ask because sometimes the line endings of cases written out on Linux and transferred to Windows can cause problems.

Any cases that you share would be treated with the utmost confidentiality. Another option would be to create a large mesh for a simple case (e.g., a cube) in FLUENT and try importing that into Caedium.

I created the Fluent case on

Submitted by Samir on August 20, 2012 - 09:23.

I created the Fluent case on the same machine, on windows.

No it does not have multiple volumes zones.

Thank you for the advice about the cube. I just made it three hours ago, natural convection with one face heated and with 2M cells , and it seems to work correctly with Caedium, it takes few minutes to import, but calculation run correctly and results are the results expected.

I will check the geometry using OpenFOAM to see if the problems comes from it, and I'll keep you informed. For the confidentiality, the administration of my company do not approve it, sorry for that.

Thank you again very much for your advices.

Another Thought

Submitted by symscape on August 20, 2012 - 10:11.

Try switching on the OpenFOAM diagnostics in Caedium, if you haven't already:

File->Preferences, Physics->OpenFOAM->Diagnostics = true

There might be additional messages that can help identify the problem.

Dimension of grid: 3Number

Submitted by Samir on August 21, 2012 - 07:25.

Dimension of grid: 3
Number of points: 4633130
Number of faces: 22938776
Number of cells: 9632188
PointGroup: 1 start: 556874 end: 4633129. Reading points...done.
PointGroup: 5 start: 0 end: 556873. Reading points...done.
FaceGroup: 49 start: 762368 end: 763615. Reading uniform faces...done.
FaceGroup: 51 start: 763616 end: 764010. Reading uniform faces...done.
FaceGroup: 52 start: 764011 end: 764953. Reading uniform faces...done.
FaceGroup: 53 start: 764954 end: 765541. Reading uniform faces...done.
FaceGroup: 54 start: 765542 end: 766129. Reading uniform faces...done.
FaceGroup: 55 start: 766130 end: 766715. Reading uniform faces...done.
FaceGroup: 56 start: 766716 end: 767307. Reading uniform faces...done.
FaceGroup: 57 start: 767308 end: 767915. Reading uniform faces...done.
FaceGroup: 58 start: 767916 end: 768510. Reading uniform faces...done.
FaceGroup: 59 start: 768511 end: 768937. Reading uniform faces...done.
FaceGroup: 60 start: 768938 end: 769364. Reading uniform faces...done.
FaceGroup: 61 start: 769365 end: 769952. Reading uniform faces...done.
FaceGroup: 62 start: 769953 end: 770540. Reading uniform faces...done.
FaceGroup: 63 start: 770541 end: 771126. Reading uniform faces...done.
FaceGroup: 64 start: 771127 end: 771718. Reading uniform faces...done.
FaceGroup: 65 start: 771719 end: 772326. Reading uniform faces...done.
FaceGroup: 66 start: 772327 end: 772921. Reading uniform faces...done.
FaceGroup: 67 start: 772922 end: 773348. Reading uniform faces...done.
FaceGroup: 68 start: 773349 end: 773775. Reading uniform faces...done.
FaceGroup: 69 start: 773776 end: 774240. Reading uniform faces...done.
FaceGroup: 70 start: 774241 end: 774705. Reading uniform faces...done.
FaceGroup: 71 start: 774706 end: 775263. Reading uniform faces...done.
FaceGroup: 86 start: 775264 end: 776759. Reading uniform faces...done.
FaceGroup: 87 start: 776760 end: 778255. Reading uniform faces...done.
FaceGroup: 88 start: 778256 end: 780433. Reading uniform faces...done.
FaceGroup: 89 start: 780434 end: 782611. Reading uniform faces...done.
FaceGroup: 91 start: 782612 end: 1497878. Reading uniform faces...done.
FaceGroup: 100 start: 1497879 end: 1981491. Reading mixed faces...done.
FaceGroup: 103 start: 1981492 end: 3603934. Reading mixed faces...done.
FaceGroup: 104 start: 3603935 end: 15712227. Reading mixed faces...done.
FaceGroup: 105 start: 15712228 end: 16558249. Reading uniform faces...done.
FaceGroup: 106 start: 16558250 end: 16561529. Reading uniform faces...done.
FaceGroup: 107 start: 16561530 end: 18049893. Reading uniform faces...done.
FaceGroup: 108 start: 18049894 end: 19158776. Reading uniform faces...done.
FaceGroup: 109 start: 19158777 end: 20530800. Reading uniform faces...done.
FaceGroup: 110 start: 20530801 end: 22377916. Reading uniform faces...done.
FaceGroup: 111 start: 22377917 end: 22739052. Reading mixed faces...done.
FaceGroup: 112 start: 22739053 end: 22892770. Reading uniform faces...done.
FaceGroup: 113 start: 22892771 end: 22908778. Reading uniform faces...done.
FaceGroup: 114 start: 22908779 end: 22938775. Reading uniform faces...done.
FaceGroup: 14 start: 0 end: 12575. Reading uniform faces...done.
FaceGroup: 15 start: 12576 end: 13227. Reading uniform faces...done.
FaceGroup: 16 start: 13228 end: 22053. Reading uniform faces...done.
FaceGroup: 17 start: 22054 end: 24851. Reading uniform faces...done.
FaceGroup: 18 start: 24852 end: 29309. Reading uniform faces...done.
FaceGroup: 19 start: 29310 end: 29815. Reading uniform faces...done.
FaceGroup: 20 start: 29816 end: 35891. Reading uniform faces...done.
FaceGroup: 21 start: 35892 end: 36715. Reading mixed faces...done.
FaceGroup: 22 start: 36716 end: 52074. Reading uniform faces...done.
FaceGroup: 23 start: 52075 end: 59032. Reading uniform faces...done.
FaceGroup: 24 start: 59033 end: 67588. Reading uniform faces...done.
FaceGroup: 25 start: 67589 end: 75894. Reading uniform faces...done.
FaceGroup: 26 start: 75895 end: 83008. Reading uniform faces...done.
FaceGroup: 27 start: 83009 end: 88575. Reading uniform faces...done.
FaceGroup: 28 start: 88576 end: 100325. Reading uniform faces...done.
FaceGroup: 29 start: 100326 end: 103063. Reading mixed faces...done.
FaceGroup: 30 start: 103064 end: 141003. Reading uniform faces...done.
FaceGroup: 31 start: 141004 end: 144159. Reading uniform faces...done.
FaceGroup: 32 start: 144160 end: 168961. Reading uniform faces...done.
FaceGroup: 33 start: 168962 end: 170749. Reading mixed faces...done.
FaceGroup: 34 start: 170750 end: 200621. Reading mixed faces...done.
FaceGroup: 35 start: 200622 end: 253320. Reading uniform faces...done.
FaceGroup: 36 start: 253321 end: 285437. Reading uniform faces...done.
FaceGroup: 37 start: 285438 end: 315382. Reading mixed faces...done.
FaceGroup: 38 start: 315383 end: 329192. Reading mixed faces...done.
FaceGroup: 39 start: 329193 end: 343286. Reading uniform faces...done.
FaceGroup: 40 start: 343287 end: 356694. Reading uniform faces...done.
FaceGroup: 41 start: 356695 end: 371258. Reading mixed faces...done.
FaceGroup: 42 start: 371259 end: 384799. Reading uniform faces...done.
FaceGroup: 43 start: 384800 end: 390014. Reading uniform faces...done.
FaceGroup: 44 start: 390015 end: 392014. Reading uniform faces...done.
FaceGroup: 45 start: 392015 end: 400075. Reading uniform faces...done.
FaceGroup: 46 start: 400076 end: 413491. Reading uniform faces...done.
FaceGroup: 48 start: 413492 end: 421246. Reading uniform faces...done.
FaceGroup: 50 start: 421247 end: 436261. Reading uniform faces...done.
FaceGroup: 72 start: 436262 end: 483473. Reading uniform faces...done.
FaceGroup: 73 start: 483474 end: 530905. Reading uniform faces...done.
FaceGroup: 75 start: 530906 end: 582518. Reading uniform faces...done.
FaceGroup: 76 start: 582519 end: 583414. Reading uniform faces...done.
FaceGroup: 77 start: 583415 end: 584404. Reading uniform faces...done.
FaceGroup: 78 start: 584405 end: 612056. Reading uniform faces...done.
FaceGroup: 79 start: 612057 end: 625946. Reading uniform faces...done.
FaceGroup: 80 start: 625947 end: 628982. Reading uniform faces...done.
FaceGroup: 81 start: 628983 end: 636572. Reading uniform faces...done.
FaceGroup: 82 start: 636573 end: 642182. Reading uniform faces...done.
FaceGroup: 84 start: 642183 end: 647762. Reading uniform faces...done.
FaceGroup: 85 start: 647763 end: 653416. Reading uniform faces...done.
FaceGroup: 90 start: 653417 end: 653972. Reading uniform faces...done.
FaceGroup: 92 start: 653973 end: 727678. Reading mixed faces...done.
FaceGroup: 93 start: 727679 end: 728072. Reading uniform faces...done.
FaceGroup: 94 start: 728073 end: 746386. Reading uniform faces...done.
FaceGroup: 95 start: 746387 end: 749680. Reading uniform faces...done.
FaceGroup: 96 start: 749681 end: 750168. Reading uniform faces...done.
FaceGroup: 97 start: 750169 end: 751152. Reading uniform faces...done.
FaceGroup: 98 start: 751153 end: 751164. Reading uniform faces...done.
FaceGroup: 99 start: 751165 end: 751302. Reading uniform faces...done.
FaceGroup: 102 start: 751303 end: 752986. Reading uniform faces...done.
FaceGroup: 83 start: 752987 end: 754436. Reading uniform faces...done.
FaceGroup: 74 start: 754437 end: 757716. Reading uniform faces...done.
FaceGroup: 47 start: 757717 end: 762367. Reading uniform faces...done.
CellGroup: 2 start: 0 end: 378871 type: 1
CellGroup: 3 start: 378872 end: 1212864 type: 1
CellGroup: 4 start: 1212865 end: 7211410 type: 1
CellGroup: 6 start: 7211411 end: 7716530 type: 1
CellGroup: 7 start: 7716531 end: 8094821 type: 1
CellGroup: 8 start: 8094822 end: 8563009 type: 1
CellGroup: 9 start: 8563010 end: 9188301 type: 1
CellGroup: 10 start: 9188302 end: 9324232 type: 1
CellGroup: 11 start: 9324233 end: 9377587 type: 1
CellGroup: 12 start: 9377588 end: 9383571 type: 1
CellGroup: 13 start: 9383572 end: 9394461 type: 1
CellGroup: 131 start: 9394462 end: 9632187 type: 1
Zone: 49 name: pj_grating type: interior. Reading zone data...done.
Zone: 51 name: int_bypass-cyl-duct-outlet type: interior. Reading zone data...done.
Zone: 52 name: int_bypass-duct-interface type: interior. Reading zone data...done.
Zone: 53 name: int_inlet-aperture-outlet-8 type: interior. Reading zone data...done.
Zone: 54 name: int_inlet-aperture-outlet-7 type: interior. Reading zone data...done.
Zone: 55 name: int_inlet-aperture-outlet-6 type: interior. Reading zone data...done.
Zone: 56 name: int_inlet-aperture-outlet-5 type: interior. Reading zone data...done.
Zone: 57 name: int_inlet-aperture-outlet-4 type: interior. Reading zone data...done.
Zone: 58 name: int_inlet-aperture-outlet-3 type: interior. Reading zone data...done.
Zone: 59 name: int_dwst-inlet-aperture-2 type: interior. Reading zone data...done.
Zone: 60 name: int_dwst-inlet-aperture-1 type: interior. Reading zone data...done.
Zone: 61 name: int_inlet-aperture-8 type: interior. Reading zone data...done.
Zone: 62 name: int_inlet-aperture-7 type: interior. Reading zone data...done.
Zone: 63 name: int_inlet-aperture-6 type: interior. Reading zone data...done.
Zone: 64 name: int_inlet-aperture-5 type: interior. Reading zone data...done.
Zone: 65 name: int_inlet-aperture-4 type: interior. Reading zone data...done.
Zone: 66 name: int_inlet-aperture-3 type: interior. Reading zone data...done.
Zone: 67 name: int_inlet-aperture-2 type: interior. Reading zone data...done.
Zone: 68 name: int_inlet-aperture-1 type: interior. Reading zone data...done.
Zone: 69 name: int_outlet-aperture-3 type: interior. Reading zone data...done.
Zone: 70 name: int_outlet-aperture-2 type: interior. Reading zone data...done.
Zone: 71 name: int_outlet-aperture-1 type: interior. Reading zone data...done.
Zone: 86 name: int_louvers-outlet type: interior. Reading zone data...done.
Zone: 87 name: int_louvers-inlet type: interior. Reading zone data...done.
Zone: 88 name: int_heaters-outlet type: interior. Reading zone data...done.
Zone: 89 name: int_heaters-inlet type: interior. Reading zone data...done.
Zone: 91 name: default-interior-2 type: interior. Reading zone data...done.
Zone: 100 name: default-interior-1 type: interior. Reading zone data...done.
Zone: 103 name: default-interior-2:103 type: interior. Reading zone data...done.
Zone: 104 name: default-interior-2:104 type: interior. Reading zone data...done.
Zone: 105 name: default-interior-2:105 type: interior. Reading zone data...done.
Zone: 106 name: default-interior-2:106 type: interior. Reading zone data...done.
Zone: 107 name: default-interior-2:107 type: interior. Reading zone data...done.
Zone: 108 name: default-interior-2:108 type: interior. Reading zone data...done.
Zone: 109 name: default-interior-2:109 type: interior. Reading zone data...done.
Zone: 110 name: default-interior-2:110 type: interior. Reading zone data...done.
Zone: 111 name: default-interior-2:111 type: interior. Reading zone data...done.
Zone: 112 name: default-interior-2:112 type: interior. Reading zone data...done.
Zone: 113 name: default-interior-2:113 type: interior. Reading zone data...done.
Zone: 114 name: default-interior-2:114 type: interior. Reading zone data...done.
Zone: 14 name: w_bypass-duct-2 type: wall. Reading zone data...done.
Zone: 15 name: w_uninsulated-gas-pipe-c type: wall. Reading zone data...done.
Zone: 16 name: w_uninsulated-gas-pipe-b type: wall. Reading zone data...done.
Zone: 17 name: w_gas-valve-02b type: wall. Reading zone data...done.
Zone: 18 name: w_gas-valve-02a type: wall. Reading zone data...done.
Zone: 19 name: w_gas-valve-01b type: wall. Reading zone data...done.
Zone: 20 name: w_uninsulated-air-pipe type: wall. Reading zone data...done.
Zone: 21 name: w_uninsulated-gas-pipe-inlet type: wall. Reading zone data...done.
Zone: 22 name: w_uninsulated-gas-pipe-a type: wall. Reading zone data...done.
Zone: 23 name: w_instrumentation type: wall. Reading zone data...done.
Zone: 24 name: w_purge-valve-2 type: wall. Reading zone data...done.
Zone: 25 name: w_purge-valve-1 type: wall. Reading zone data...done.
Zone: 26 name: w_gas-valve-01a type: wall. Reading zone data...done.
Zone: 27 name: w_goulotte type: wall. Reading zone data...done.
Zone: 28 name: w_oil-pipes-2 type: wall. Reading zone data...done.
Zone: 29 name: w_oil-pipes-1 type: wall. Reading zone data...done.
Zone: 30 name: w_pipings-supports type: wall. Reading zone data...done.
Zone: 31 name: w_oil-tank type: wall. Reading zone data...done.
Zone: 32 name: w_instrumentation-panel-32 type: wall. Reading zone data...done.
Zone: 33 name: w_insulated-air-pipe-o type: wall. Reading zone data...done.
Zone: 34 name: w_insulated-air-pipe-i type: wall. Reading zone data...done.
Zone: 35 name: w_insulated-gas-pipe-o type: wall. Reading zone data...done.
Zone: 36 name: w_insulated-gas-pipe-i type: wall. Reading zone data...done.
Zone: 37 name: w_enclosure-ground type: wall. Reading zone data...done.
Zone: 38 name: w_enclosure-roof type: wall. Reading zone data...done.
Zone: 39 name: w_enclosure-x- type: wall. Reading zone data...done.
Error:
Failed: Import Geometry
Unexpected process exit.

--> FOAM FATAL ERROR:
Do not understand characters: +
on line 27573207

From function fluentMeshToFoam::lexer
in file fluent3DMeshToFoam.L at line 753.

FOAM exiting

This is another case I tested, but the error type is the same...

PS: I tested on a Linux machine with OpenFOAM commands, the same error occurs. I will try other examples.

Multiple Volumes

Submitted by symscape on August 21, 2012 - 08:10.

From this diagnostic I see:

  • 9,632,188 cells, i.e., 9.6M cells
  • 12 cell groups, i.e., 12 volumes
  • References to insulated pipes

I'm guessing that there are multiple volumes (cell groups/zones) because you want to perform conjugate heat transfer (CHT, solid-fluid heat conduction). Caedium does not support CHT, so I'm not sure this exercise is going to be useful.

If you want to explore Caedium's heat transfer capabilities I suggest you try single volume flow domains.

Also have you tried looking at line 27,573,207 in the case file that is causing the problem? I think that syntax may be related to CHT and is not supported by the import filter.

BC syntax problem

Submitted by Samir on August 21, 2012 - 08:50.

I think it is a boundary condition syntax problem. I have to change the names for some of them in order to suite OpenFOAM syntax ( no / and + ... ) .

Thank you for your explanations, I will not try to do the exercise, I was just exploring the capacities to import a huge mesh into Caedium.
I will make the changes and try again.

Thank you again for your reactivity.

PS: It works perfectly for the import, it is a syntax problem, I deleted all the signs as ":", "/", "+" and "-", leaving only "_" and it imports all my meshings.

Thank You again!

Thanks for the update

Submitted by symscape on August 20, 2012 - 09:51.

Thanks for the update.

I just tried an 8M cell case created in Caedium, exported to FLUENT (.msh 1.54GB) and then imported back into Caedium. It worked fine with a peak import process size of about 5.3GB.

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