[lhsihan]

Hi Experts,
I have run Openfoam motorbike example on my instance and when checking mesh have got the error that "Failed 1 mesh checks".

Could you please help me check the root cause for this mesh? I couldn't understand why the mesh was wrong.

The steps to reproduce the error that:
1. cp -r $FOAM_TUTORIALS/incompressible/simpleFoam/motorBike .
2. Run allrun script:

[openfoam@testopenfoammove run]# cd motorBike
[openfoam@testopenfoammove motorBike]# ./Allrun
Running surfaceFeatureExtract on /home/openfoam/OpenFOAM/root-v1806/run/motorBike 
Running blockMesh on /home/openfoam/OpenFOAM/root-v1806/run/motorBike
Running decomposePar on /home/openfoam/OpenFOAM/root-v1806/run/motorBike
Running snappyHexMesh in parallel on /home/openfoam/OpenFOAM/root-v1806/run/motorBike using 6  processes
Running patchSummary in parallel on/home/openfoam/OpenFOAM/root-v1806/run/motorBike using 6  processes
Running potentialFoam in parallel on /home/openfoam/OpenFOAM/root-v1806/run/motorBike using 6  processes
Running simpleFoam in parallel on /home/openfoam/OpenFOAM/root-v1806/run/motorBike using 6  processes
Running reconstructParMesh on /home/openfoam/OpenFOAM/root-v1806/run/motorBike
Running reconstructPar on /home/openfoam/OpenFOAM/root-v1806/run/motorBike

3. CheckMesh:

[openfoam@testopenfoammove motorBike]$ checkMesh
/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v1806                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : v1806
Arch   : "LSB;label=32;scalar=64"
Exec   : checkMesh
Date   : Dec 10 2018
Time   : 02:06:27
Host   : "testopenfoammove"
PID    : 7852
I/O    : uncollated
Case   : /home/openfoam/OpenFOAM/openfoam-v1806/run/motorBike
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

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

Create mesh for time = 500

Time = 500

Mesh stats
    points:           405037
    faces:            1104871
    internal faces:   1054763
    cells:            352592
    faces per cell:   6.12502
    boundary patches: 72
    point zones:      0
    face zones:       0
    cell zones:       0

Overall number of cells of each type:
    hexahedra:     307275
    prisms:        7321
    wedges:        988
    pyramids:      3
    tet wedges:    1763
    tetrahedra:    58
    polyhedra:     35184
    Breakdown of polyhedra by number of faces:
        faces   number of cells
            4   3955
            5   6547
            6   5481
            7   3023
            8   1311
            9   10609
           10   13
           11   6
           12   2334
           13   3
           14   1
           15   1633
           17   1
           18   265
           21   2

Checking topology...
    Boundary definition OK.
    Cell to face addressing OK.
    Point usage OK.
    Upper triangular ordering OK.
    Face vertices OK.
    Number of regions: 1 (OK).

Checking patch topology for multiply connected surfaces...
                   Patch    Faces   Points                  Surface topology
            frontAndBack      360      420  ok (non-closed singly connected)
                   inlet       72       90  ok (non-closed singly connected)
                  outlet       72       90  ok (non-closed singly connected)
               lowerWall     5349     5677  ok (non-closed singly connected)
               upperWall      160      189  ok (non-closed singly connected)
			   
    motorBike_frt-fairing:001%1     5309     9910  multiply connected (shared edge)
	
	
    motorBike_windshield:002%2       50       83  ok (non-closed singly connected)
    motorBike_rr-wh-rim:005%5      127      219  ok (non-closed singly connected)
    motorBike_rr-wh-rim:010%10      354      672  ok (non-closed singly connected)
    motorBike_fr-wh-rim:011%11      500      826  ok (non-closed singly connected)
    motorBike_fr-wh-brake-disk:012%12       46       88  ok (non-closed singly connected)
    motorBike_frame:016-shadow%13      102      224  ok (non-closed singly connected)
    motorBike_rear-susp:014%14      848     1508  ok (non-closed singly connected)
    motorBike_rear-susp:014-shadow%15      437     1175  ok (non-closed singly connected)
    motorBike_frame:016%16       65      173  ok (non-closed singly connected)
    motorBike_rr-wh-rim:005-shadow%17       62      164  ok (non-closed singly connected)
    motorBike_rr-wh-chain-hub:022%22      128      220  ok (non-closed singly connected)
    motorBike_rearseat%24      421      512  ok (non-closed singly connected)
    motorBike_frt-fairing%25      617      853  ok (non-closed singly connected)
    motorBike_windshield%26      372      815  ok (non-closed singly connected)
    motorBike_headlights%27      156      257  ok (non-closed singly connected)
    motorBike_driversseat%28      350      531  ok (non-closed singly connected)
    motorBike_rear-body%29     2051     2519  ok (non-closed singly connected)
    motorBike_fuel-tank%30      878     1219  ok (non-closed singly connected)
    motorBike_exhaust%31     2334     2994  ok (non-closed singly connected)
    motorBike_rr-wh-rim%32     1377     1741  ok (non-closed singly connected)
    motorBike_fr-mud-guard%33      637     1194  ok (non-closed singly connected)
    motorBike_fr-wh-rim%34      574      796  ok (non-closed singly connected)
    motorBike_fr-wh-brake-disk%35      428      687  ok (non-closed singly connected)
    motorBike_fr-brake-caliper%36      157      208  ok (non-closed singly connected)
    motorBike_fr-wh-tyre%37     1108     1550  ok (non-closed singly connected)
      motorBike_hbars%38      520      669  ok (non-closed singly connected)
    motorBike_fr-forks%39     1095     1459  ok (non-closed singly connected)
      motorBike_chain%40      457      570  ok (non-closed singly connected)
    motorBike_rr-wh-tyre%41     1846     2425  ok (non-closed singly connected)
    motorBike_square-dial%42        6       12  ok (non-closed singly connected)
    motorBike_round-dial%43       15       29  ok (non-closed singly connected)
    motorBike_dial-holder%44       88      133  ok (non-closed singly connected)
	
	
    motorBike_rear-susp%45     1725     2170  multiply connected (shared edge)
	
    motorBike_rear-brake-lights%46       54       87  ok (non-closed singly connected)
    motorBike_rear-light-bracket%47      158      207  ok (non-closed singly connected)
      motorBike_frame%48     2007     2455  ok (non-closed singly connected)
    motorBike_rear-mud-guard%49      635     1203  ok (non-closed singly connected)
    motorBike_rear-susp-spring-damp%50       91      193  ok (non-closed singly connected)
    motorBike_fairing-inner-plate%51      433      558  ok (non-closed singly connected)
    motorBike_clutch-housing%52      929     1113  ok (non-closed singly connected)
    motorBike_radiator%53       44       77  multiply connected (shared edge)
    motorBike_water-pipe%54      101      114  multiply connected (shared edge)
    motorBike_water-pump%55       73       99  ok (non-closed singly connected)
     motorBike_engine%56     2301     2575  ok (non-closed singly connected)
    motorBike_rear-shock-link%57       28       61  ok (non-closed singly connected)
    motorBike_rear-brake-fluid-pot-bracket%58       39       79  ok (non-closed singly connected)
    motorBike_rear-brake-fluid-pot%59       51       62  ok (non-closed singly connected)
    motorBike_footpeg%60       90      125  ok (non-closed singly connected)
    motorBike_rr-wh-chain-hub%61      127      241  ok (non-closed singly connected)
    motorBike_rear-brake-caliper%62      145      177  ok (non-closed singly connected)
    motorBike_rider-helmet%65      760     1002  ok (non-closed singly connected)
    motorBike_rider-visor%66      165      266  ok (non-closed singly connected)
    motorBike_rider-boots%67     1008     1332  ok (non-closed singly connected)
    motorBike_rider-gloves%68      309      398  ok (non-closed singly connected)
    motorBike_rider-body%69     4584     5790  multiply connected (shared edge)
    motorBike_frame:0%70       37       61  ok (non-closed singly connected)
    motorBike_frt-fairing:001-shadow%74     3285     8417  multiply connected (shared edge)
    motorBike_windshield-shadow%75      266      706  ok (non-closed singly connected)
    motorBike_fr-mud-guard-shadow%81      317      879  ok (non-closed singly connected)
    motorBike_fr-wh-brake-disk-shadow%83      209      480  ok (non-closed singly connected)
    motorBike_rear-mud-guard-shadow%84      420     1052  ok (non-closed singly connected)
    motorBike_rear-susp-spring-damp-shadow%85       57      157  ok (non-closed singly connected)
    motorBike_radiator-shadow%86       28       61  ok (non-closed singly connected)
    motorBike_rear-shock-link-shadow%87        8       24  ok (non-closed singly connected)
    motorBike_rear-brake-fluid-pot-bracket-shadow%88       27       66  ok (non-closed singly connected)
    motorBike_rr-wh-chain-hub-shadow%89       69      185  ok (non-closed singly connected)

Checking faceZone topology for multiply connected surfaces...
    No faceZones found.
  <<Writing 16 conflicting points to set nonManifoldPoints

Checking basic cellZone addressing...
    No cellZones found.

Checking geometry...
    Overall domain bounding box (-5 -4 0) (15 4 8)
    Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
    Mesh has 3 solution (non-empty) directions (1 1 1)
    Boundary openness (3.89779e-18 1.03836e-16 -8.98276e-16) OK.
    Max cell openness = 9.34416e-16 OK.
    Max aspect ratio = 41.1396 OK.
    Minimum face area = 7.24969e-07. Maximum face area = 1.01339.  Face area magnitudes OK.
    Min volume = 9.82386e-09. Max volume = 1.00376.  Total volume = 1279.67.  Cell volumes OK.
    Mesh non-orthogonality Max: 64.9585 average: 9.91962
    Non-orthogonality check OK.
    Face pyramids OK.
 ***Max skewness = 10.2712, 11 highly skew faces detected which may impair the quality of the results
  <<Writing 11 skew faces to set skewFaces
    Coupled point location match (average 0) OK.

Failed 1 mesh checks.

End

[hjasak]

Hi,

You can safely proceed - the mesh is fine.

The checkMesh utility is very strict and the code will run fine on this mesh.

Good luck,

Hrvoje

[lhsihan]

Originally Posted by hjasak

Hi,

You can safely proceed - the mesh is fine.

The checkMesh utility is very strict and the code will run fine on this mesh.

Good luck,

Hrvoje

Thanks hjasak a lot for the reply.