[gdsilva]

Hello, everyone.


I am trying to use NACA 0012 meshs provided by NASA (https://turbmodels.larc.nasa.gov/naca0012_grids.html).


These are the steps I've made so far:

• downloaded the 897 x 257 mesh (https://turbmodels.larc.nasa.gov/NAC...-257.p3dfmt.gz);
• converted it to OpenFOAM using the following command plot3dToFoam -noBlank n0012_897-257.p3dfmt;
• used the autoPatch -overwrite 45 to set the patches;
• and finally applied the checkMesh command, which gave that everything was ok, except the aspect ratio of some cells.

These are the terminal output from each command:

plot3dToFoam -noBlank n0012_897-257.p3dfmt

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  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   : plot3dToFoam -noBlank ../../../meshs/n0012_897-257.p3dfmt
Date   : Nov 17 2024
Time   : 22:15:05
Host   : nitro
PID    : 18342
I/O    : uncollated
Case   : /home/gabriel/Documents/cfd-models-comparison/simulations/3D/simpleFoam/kOmegaSST
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

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

Reading 1 blocks
block 0 nx:2 ny:897 nz:257
Reading block points
block 0:
Reading 461058 x coordinates...
Reading 461058 y coordinates...
Reading 461058 z coordinates...
Looking at cell 0 0 0 to determine orientation.
Right-handed block.

Merged points within 1e-15 distance. Merged from 461058 down to 460672 points.
Creating cells
Creating boundary patches
--> FOAM Warning : 
    From Foam::polyMesh::polyMesh(const Foam::IOobject&, Foam::pointField&&, const Foam::cellShapeList&, const Foam::faceListList&, const Foam::wordList&, const Foam::wordList&, const Foam::word&, const Foam::word&, const Foam::wordList&, bool)
    in file meshes/polyMesh/polyMeshFromShapeMesh.C at line 640
    Found 460672 undefined faces in mesh; adding to default patch defaultFaces
Writing polyMesh
End

autoPatch -overwrite 45

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  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   : autoPatch -overwrite 45
Date   : Nov 17 2024
Time   : 22:15:10
Host   : nitro
PID    : 18388
I/O    : uncollated
Case   : /home/gabriel/Documents/cfd-models-comparison/simulations/3D/simpleFoam/kOmegaSST
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

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

Create polyMesh for time = 0

Mesh read in = 1.01 s


Feature:45
minCos :0.707107

Assigned 512 faces to patch auto0

Assigned 229376 faces to patch auto1

Assigned 229376 faces to patch auto2

Assigned 512 faces to patch auto3

Assigned 896 faces to patch auto4

End

checkMesh

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  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   : Nov 17 2024
Time   : 22:15:19
Host   : nitro
PID    : 18474
I/O    : uncollated
Case   : /home/gabriel/Documents/cfd-models-comparison/simulations/3D/simpleFoam/kOmegaSST
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
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:           460672
    internal points:  0
    faces:            918464
    internal faces:   457792
    cells:            229376
    faces per cell:   6
    boundary patches: 6
    point zones:      0
    face zones:       0
    cell zones:       0

Overall number of cells of each type:
    hexahedra:     229376
    prisms:        0
    wedges:        0
    pyramids:      0
    tet wedges:    0
    tetrahedra:    0
    polyhedra:     0

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
    defaultFaces        0        0        ok (empty)                        
    auto0               512      1026     ok (non-closed singly connected)  
    auto1               229376   230336   ok (non-closed singly connected)  
    auto2               229376   230336   ok (non-closed singly connected)  
    auto3               512      1024     ok (non-closed singly connected)  
    auto4               896      1794     ok (non-closed singly connected)  
    ".*"                460672   460672   ok (closed singly connected)      


Checking faceZone topology for multiply connected surfaces...
    No faceZones found.

Checking basic cellZone addressing...
    No cellZones found.

Checking basic pointZone addressing...
    No pointZones found.

Checking geometry...
    Overall domain bounding box (-484.457 -1 -507.807) (501 0 507.807)
    Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
    Mesh has 3 solution (non-empty) directions (1 1 1)
    Boundary openness (-7.45106e-19 7.70971e-15 2.26771e-19) OK.
 ***High aspect ratio cells found, Max aspect ratio: 3.17847e+07, number of cells 87404
  <<Writing 87404 cells with high aspect ratio to set highAspectRatioCells
    Minimum face area = 9.5796e-11. Maximum face area = 843.777.  Face area magnitudes OK.
    Min volume = 9.5796e-11. Max volume = 843.777.  Total volume = 875558.  Cell volumes OK.
    Mesh non-orthogonality Max: 19.8306 average: 1.63523
    Non-orthogonality check OK.
    Face pyramids OK.
    Max skewness = 0.201756 OK.
    Coupled point location match (average 0) OK.

Failed 1 mesh checks.

 End

As the last output shows, there are some cells that their aspect ratio are not ok.

How can I improve this mesh or identify the high aspect ratio cells? And what should I do if I identify them?


Thank you, guys!