[peterksh]

Hello everyone
I am working on a problem in openFOAM 2406. My task is to replicate a simulation which has already been performed in Ansys Fluent. The simulation in question is a tutorial case from Fluent tutorials regarding simulation of porous media. It is a flow simulation through a catalytic converter. I have already successfully performed the simulation in Fluent by following the tutorial pdf and am now working in openFOAM.

I have imported the mesh from fluent. I have looked at the settings in fluent and tried my best to set up the case in openFOAM. I am using porousSimpleFoam for this.



Problem: I am getting a floating point exception error.

Solutions tried: My first search on this forum led me to believe it was a meshing problem. I ran checkMesh, found out 99 non orthogonal faces. To tackle the same, I tried increasing the 'nNonOrthogonalCorrectors' value. That did not work. I have also tried disabling floating point exception handling.

Further searching has given me two ideas. One is my understanding of the output given by checkMesh is wrong. Or the other is that my boundary conditions are incorrect. I am leaning on the latter. I am sorry for this being my skill issue, but I really lack the theoretical background to find out which condition is wrong at this point. That is where I'd really like some help.



Attaching a drive link with all the files.

https://drive.google.com/drive/folde...usp=drive_link


Folders (3):
catcon: my case directory with all the files. (including 'flntgz.msh' file exported from fluent)
ansys reference data: screenshots of settings in fluent which I have referenced for case setup
error data: txt files of terminal output on running checkMesh and porousSimpleFoam.

two outputs have been attached, one with exception handling enabled and one with disabled. Could not attach it in the post due to character limitations.

Attaching the checkMesh result below as well for quick reference.


checkMesh output:

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2406                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : _be01ca78-20240625 OPENFOAM=2406 version=2406
Arch   : "LSB;label=32;scalar=64"
Exec   : checkMesh
Date   : Sep 30 2024
Time   : 23:17:22
Host   : localhost.localdomain
PID    : 30915
I/O    : uncollated
Case   : /home/peter/opfm/catcon
nProcs : 1
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0

Check mesh...

Time = 0

Mesh stats 
    points:           2274333
    faces:            3103361
    internal faces:   2897633
    cells:            550560
    faces per cell:   10.8998002
    boundary patches: 72
    point zones:      0
    face zones:       25
    cell zones:       21

Overall number of cells of each type:
    hexahedra:     3742
    prisms:        1687
    wedges:        583
    pyramids:      252
    tet wedges:    9
    tetrahedra:    859
    polyhedra:     543428
    Breakdown of polyhedra by number of faces:
        faces   number of cells
            4   4
            5   18
            6   407
            7   39635
            8   116666
            9   37892
           10   51796
           11   71808
           12   55408
           13   53374
           14   50626
           15   36239
           16   18754
           17   7368
           18   2407
           19   706
           20   237
           21   60
           22   19
           23   1
           24   3

Checking topology...
    Boundary definition OK.
    Cell to face addressing OK.
 ***Unused points found in the mesh, number unused by faces: 175923 number unused by cells: 175923
  <<Writing 175923 unused points to set unusedPoints
  <<Found 130 neighbouring cells with multiple inbetween faces.
    Upper triangular ordering OK.
  <<Writing 260 unordered faces to set upperTriangularFace
    Face vertices OK.
   *Number of regions: 17
    The mesh has multiple regions which are not connected by any face.
  <<Writing region information to "0/cellToRegion"
  <<Writing region 0 with 35632 cells to cellSet region0
  <<Writing region 1 with 346455 cells to cellSet region1
  <<Writing region 2 with 33106 cells to cellSet region2
  <<Writing region 3 with 2063 cells to cellSet region3
  <<Writing region 4 with 7631 cells to cellSet region4
  <<Writing region 5 with 2100 cells to cellSet region5
  <<Writing region 6 with 2181 cells to cellSet region6
  <<Writing region 7 with 2262 cells to cellSet region7
  <<Writing region 8 with 22295 cells to cellSet region8
  <<Writing region 9 with 7800 cells to cellSet region9
  <<Writing region 10 with 3263 cells to cellSet region10
  <<Writing region 11 with 35816 cells to cellSet region11
  <<Writing region 12 with 41771 cells to cellSet region12
  <<Writing region 13 with 4102 cells to cellSet region13
  <<Writing region 14 with 3132 cells to cellSet region14
  <<Writing region 15 with 477 cells to cellSet region15
  <<Writing region 16 with 474 cells to cellSet region16

Checking patch topology for multiply connected surfaces...
                   Patch    Faces   Points  Surface topology
    sensing_element-65-solid:257:6501      220      438  ok (non-closed singly connected)
    quadribbed_body_bottom_af0-solid:1:6500     3574     3502  multiply connected (shared edge)
    quadribbed_body_bottom_af0-solid:1:6499    13820    26708  ok (non-closed singly connected)
    quadribbed_body_top_af1-solid:1:6498    14642    28485  ok (non-closed singly connected)
    quadribbed_body_top_af1-solid:1:6497     4432     4356  multiply connected (shared edge)
    pipe_connetions_cc-71-solid1:1:6496     3216     3032  multiply connected (shared edge)
    pipe_connetions_cc-solid1:1:6495     3116     2956  multiply connected (shared edge)
                  outlet      778     1320  ok (non-closed singly connected)
                   inlet      784     1332  ok (non-closed singly connected)
    sensor_innertube-67-solid:266      495      991  ok (non-closed singly connected)
    quadribbed_body_bottom_af0-solid:265     4360     4353  multiply connected (shared edge)
    sensor_protectiontube-66-solid1:262    21470    20385  multiply connected (shared edge)
    sensor_protectiontube-66-solid1:261      969     1273  ok (non-closed singly connected)
    quadribbed_body_top_af1-solid:260      185      370  ok (non-closed singly connected)
    quadribbed_body_top_af1-solid:259     4578     4549  multiply connected (shared edge)
    socket_for_sensor_solid_1-solid1:258      921     1661  ok (non-closed singly connected)
    sensing_element-65-solid:257    21660    21390  multiply connected (shared edge)
                    out1      170      321  ok (non-closed singly connected)
                     in1      170      321  ok (non-closed singly connected)
    quadribbed_body_bottom_af0-solid-welding_2-54-solid1      192      192  multiply connected (shared edge)
    quadribbed_body_top_af1-solid-welding_2-54-solid1      220      214  multiply connected (shared edge)
    pipe_connetions_cc-solid1-welding_2-54-solid1      496      496  multiply connected (shared edge)
    welding_2-54-solid1:1      281      564  ok (non-closed singly connected)
    sensor_innertube-67-solid:1    32132    29963  multiply connected (shared edge)
    quadribbed_body_bottom_af0-solid:1     3636     3559  multiply connected (shared edge)
    quadribbed_body_bottom_af0-solid-recessed_cushioningmat-solid1     2800     2795  multiply connected (shared edge)
    honeycomb-solid1-recessed_cushioningmat-solid1     3676     3676  multiply connected (shared edge)
    quadribbed_body_bottom_af0-solid-recessed_cushioningmat_af0-solid1     2818     2810  multiply connected (shared edge)
    honeycomb_af0-solid1-recessed_cushioningmat_af0-solid1     3674     3674  multiply connected (shared edge)
    quadribbed_body_bottom_af0-solid-siderings-73-solid1      634      635  multiply connected (shared edge)
    recessed_cushioningmat-solid1-siderings-73-solid1     1168     1165  multiply connected (shared edge)
    honeycomb-solid1-siderings-73-solid1      708      700  multiply connected (shared edge)
    siderings-73-solid1:1     1580     1547  multiply connected (shared edge)
    quadribbed_body_bottom_af0-solid-siderings-72-solid1      652      652  multiply connected (shared edge)
    recessed_cushioningmat-solid1-siderings-72-solid1     1208     1203  multiply connected (shared edge)
    honeycomb-solid1-siderings-72-solid1      728      720  multiply connected (shared edge)
    siderings-72-solid1:1     1630     1601  multiply connected (shared edge)
    quadribbed_body_bottom_af0-solid-siderings-solid1      656      653  multiply connected (shared edge)
    recessed_cushioningmat_af0-solid1-siderings-solid1     1238     1236  multiply connected (shared edge)
    honeycomb_af0-solid1-siderings-solid1      754      747  multiply connected (shared edge)
      siderings-solid1:1     1676     1641  multiply connected (shared edge)
    quadribbed_body_bottom_af0-solid-siderings_af0-solid1      626      628  multiply connected (shared edge)
    recessed_cushioningmat_af0-solid1-siderings_af0-solid1     1160     1159  multiply connected (shared edge)
    honeycomb_af0-solid1-siderings_af0-solid1      692      683  multiply connected (shared edge)
    siderings_af0-solid1:1     1572     1558  multiply connected (shared edge)
    quadribbed_body_bottom_af0-solid-welding_2-solid1      196      195  multiply connected (shared edge)
    quadribbed_body_top_af1-solid-welding_2-solid1      212      209  multiply connected (shared edge)
    pipe_connetions_cc-71-solid1-welding_2-solid1      500      496  multiply connected (shared edge)
    sensor_innertube-67-solid-sensor_protectiontube-66-solid1     2504     2504  multiply connected (shared edge)
    quadribbed_body_top_af1-solid-sensor_protectiontube-66-solid1      294      293  multiply connected (shared edge)
    sensor_protectiontube-66-solid1:1     1524     3046  ok (non-closed singly connected)
      welding_2-solid1:1      286      575  ok (non-closed singly connected)
    quadribbed_body_bottom_af0-solid-quadribbed_body_top_af1-solid     8956     8980  multiply connected (shared edge)
    quadribbed_body_top_af1-solid-recessed_cushioningmat-solid1     2924     2920  multiply connected (shared edge)
    quadribbed_body_top_af1-solid-recessed_cushioningmat_af0-solid1     2966     2960  multiply connected (shared edge)
    quadribbed_body_top_af1-solid-siderings-73-solid1      654      656  multiply connected (shared edge)
    quadribbed_body_top_af1-solid-siderings-72-solid1      664      665  multiply connected (shared edge)
    quadribbed_body_top_af1-solid-siderings-solid1      682      680  multiply connected (shared edge)
    quadribbed_body_top_af1-solid-siderings_af0-solid1      648      647  multiply connected (shared edge)
    quadribbed_body_top_af1-solid:1     3920     3842  multiply connected (shared edge)
    pipe_connetions_cc-71-solid1-quadribbed_body_bottom_af0-solid      690      692  multiply connected (shared edge)
    pipe_connetions_cc-71-solid1-quadribbed_body_top_af1-solid      698      699  multiply connected (shared edge)
    pipe_connetions_cc-71-solid1:1      841     1682  ok (non-closed singly connected)
    pipe_connetions_cc-solid1-quadribbed_body_bottom_af0-solid      622      623  multiply connected (shared edge)
    pipe_connetions_cc-solid1-quadribbed_body_top_af1-solid      690      692  multiply connected (shared edge)
    pipe_connetions_cc-solid1:1      838     1674  ok (non-closed singly connected)
    quadribbed_body_top_af1-solid-socket_for_sensor_solid_1-solid1      370      370  multiply connected (shared edge)
    socket_for_sensor_solid_1-solid1:1      549     1098  ok (non-closed singly connected)
    sensing_element-65-solid-sensor_innertube-67-solid     5606     5511  multiply connected (shared edge)
    sensing_element-65-solid-sensor_protectiontube-66-solid1      300      288  multiply connected (shared edge)
    sensing_element-65-solid-socket_for_sensor_solid_1-solid1     1098     1098  multiply connected (shared edge)
    sensing_element-65-solid:1      329      658  ok (non-closed singly connected)
                    ".*"   205728   225391  multiply connected (shared edge)

Detected 239987 bad edges (possibly relevant for finite-area)

Checking faceZone topology for multiply connected surfaces...
                FaceZone    Faces   Points                  Surface topology
    interior--welding_2-54-solid1     1786     1902  multiply connected (shared edge)
    interior--welding_2-solid1     1791     1907  multiply connected (shared edge)
    interior--pipe_connetions_cc-solid1    15292    14864  multiply connected (shared edge)
    interior--socket_for_sensor_solid_1-solid1    24486    21393  multiply connected (shared edge)
    interior--sensing_element-65-solid   261154   220882  multiply connected (shared edge)
    interior--sensor_innertube-67-solid   207167   179648  multiply connected (shared edge)
    interior--pipe_connetions_cc-71-solid1    16021    15470  multiply connected (shared edge)
    interior--fluid:substrate:2    73326    55473  multiply connected (shared edge)
       interior--fluid:3   156278   113388  multiply connected (shared edge)
    interior--recessed_cushioningmat_af0-solid1    42885    39359  multiply connected (shared edge)
    interior--sensor_protectiontube-66-solid1   127338   113340  multiply connected (shared edge)
       interior--fluid:0  1278464   891753  multiply connected (shared edge)
    interior--siderings-solid1    11096    10909  multiply connected (shared edge)
    interior--siderings-72-solid1    10649    10518  multiply connected (shared edge)
    interior--siderings-73-solid1    10221    10099  multiply connected (shared edge)
    interior--fluid:substrate:1    72314    54691  multiply connected (shared edge)
    interior--recessed_cushioningmat-solid1    41795    38478  multiply connected (shared edge)
    interior--siderings_af0-solid1     9975     9871  multiply connected (shared edge)
    interior--quadribbed_body_bottom_af0-solid   175079   162834  multiply connected (shared edge)
       interior--fluid:1   169162   120900  multiply connected (shared edge)
    interior--quadribbed_body_top_af1-solid   188517   175709  multiply connected (shared edge)
        honeycomb-solid1      695     1387  ok (non-closed singly connected)
    honeycomb_af0-solid1      738     1473  ok (non-closed singly connected)
      honeycomb-solid1:1      709     1415  ok (non-closed singly connected)
    honeycomb_af0-solid1:1      695     1387  ok (non-closed singly connected)
  <<Writing 2097438 conflicting points to set nonManifoldPoints

Checking basic cellZone addressing...
                CellZone        Cells       Points       VolumeBoundingBox
    quadribbed_body_top_af1-solid        35632       175777  140488.5687 (-89.25303047 -495.3971674 126.6885722) (92.00181648 -420.6894226 431.8766174)
                fluid:1        33570       120900  364948.8778 (-67.35107436 -493.3719532 85.38852855) (67.62889772 -376.3692818 188.2706778)
    quadribbed_body_bottom_af0-solid        33106       162902  129282.6741 (-89.18355249 -442.9903589 141.0764618) (92.0444393 -390.6283942 431.8763428)
    siderings_af0-solid1         2063         9875  5538.543623 (-65.02862755 -493.3960695 371.06991) (69.9717266 -392.6567879 375.7563556)
    recessed_cushioningmat-solid1         7631        38482  140909.9657 (-67.29843546 -493.3788712 189.5840797) (68.62098676 -392.6321115 267.7647698)
      fluid:substrate:1        13647        54691  782565.9499 (-62.31094676 -488.3775689 186.6470244) (63.64515801 -397.640984 270.7017878)
    siderings-73-solid1         2100        10103  5532.214945 (-67.3300333 -493.3739302 186.5843062) (67.66477203 -392.6306958 191.2707634)
    siderings-72-solid1         2181        10522  5533.248115 (-66.34006556 -493.3846924 266.0781007) (68.65987514 -392.6450566 270.7645569)
       siderings-solid1         2262        10913  5533.676383 (-66.02127606 -493.3870487 291.5760985) (68.97755891 -392.6451234 296.2625829)
                fluid:0       254574       891753  406230.5489 (-64.98911829 -493.3985064 374.0696653) (69.98967841 -392.656759 481.4665707)
    sensor_protectiontube-66-solid1        22295       113341  327.5374673 (-42.68133668 -480.8622351 390.9661809) (-23.50691186 -459.7457359 409.1832804)
    recessed_cushioningmat_af0-solid1         7800        39363  140896.0812 (-65.98622217 -493.3937832 294.5644307) (69.93310547 -392.6478643 372.7565797)
                fluid:3        30842       113388  238837.7495 (-66.30253869 -493.3864609 269.0778708) (68.94127875 -392.6408651 293.2628044)
      fluid:substrate:2        13822        55473  782645.0457 (-61.00912665 -488.3921419 291.6387288) (64.94941023 -397.6537144 375.6936107)
    pipe_connetions_cc-71-solid1         3263        15474  19776.58067 (-26.98878116 -451.360631 84.38826318) (26.99423409 -374.6371539 163.332589)
    sensor_innertube-67-solid        35816       179649  301.0792091 (-42.25021107 -480.5370971 392.6253623) (-25.04204015 -460.6072002 408.7350925)
    sensing_element-65-solid        41771       220882  2515.582575 (-50.10277567 -490.4136124 396.0486906) (-30.18830638 -467.1138687 415.8363787)
    socket_for_sensor_solid_1-solid1         4102        21393  5850.789181 (-53.73747886 -493.0283601 389.9834713) (-21.51146424 -458.4651551 419.7203729)
    pipe_connetions_cc-solid1         3132        14868  19666.48647 (-23.91994322 -470.0276303 420.8223445) (30.7930795 -416.0570606 481.4917884)
       welding_2-solid1          477         1919  524.1464666 (-28.98954527 -448.0972039 125.1002025) (28.99555016 -397.9132508 155.662292)
    welding_2-54-solid1          474         1914  525.6332165 (-25.79293374 -472.0130345 430.7962726) (32.18635419 -414.0590558 434.4954346)

Checking basic pointZone addressing...
    No pointZones found.

Checking geometry...
    Overall domain bounding box (-89.26570129 -495.4034358 84.38024139) (92.06241608 -374.6228638 481.4920349)
    Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
    Mesh has 3 solution (non-empty) directions (1 1 1)
    Boundary openness (-2.692040361e-17 -3.0703598e-16 -2.291180947e-17) OK.
    Max cell openness = 3.150474567e-16 OK.
    Max aspect ratio = 40.46283584 OK.
    Minimum face area = 1.40953289e-05. Maximum face area = 107.5372978.  Face area magnitudes OK.
    Min volume = 7.388465188e-06. Max volume = 1400.97198.  Total volume = 3198430.98.  Cell volumes OK.
    Mesh non-orthogonality Max: 77.49293932 average: 9.629569954
   *Number of severely non-orthogonal (> 70 degrees) faces: 99.
    Non-orthogonality check OK.
  <<Writing 99 non-orthogonal faces to set nonOrthoFaces
    Face pyramids OK.
    Max skewness = 3.563607979 OK.
    Coupled point location match (average 0) OK.

Failed 1 mesh checks.

End