[losiola]

Hello ,


I am making a 2D airfoil simulation i ve found that Construct2D makes good mesh so i made 2D mesh with it but once i import it to OpenFoam and make a quality check I get Horrible quality mesh report Can you please help me identify the Problem



here are the details :




so i ve created a mesh O-grid mesh with elliptic topology (even though my TE is sharp i went for it because its what i am looking for ) so once i Copy the file to my openFoam case i use this command :

 plot3dToFoam naca.p3d -2D 1 -singleBlock -noBlank

i get this result with a warning :

Reading 2D case by extruding points by 1 in z direction.

Create time

Reading 1 blocks
block 0 nx:200 ny:100 nz:2
Reading block points
block 0:
Reading 20000 x coordinates...
Reading 20000 y coordinates...
Extruding 20000 points in z direction...
Looking at cell 0 0 0 to determine orientation.
Left-handed block.

Merged points within 2.220446049e-16 distance. Merged from 40000 down to 39800 points.
Creating cells
Creating boundary patches
--> FOAM Warning : 
    From function Foam::polyMesh::polyMesh(const Foam::IOobject&,  const Foam::Xfer<Foam::Field<Foam::Vector<double> >  >&, const cellShapeList&, const faceListList&, const  wordList&, const wordList&, const Foam::word&, const  Foam::word&, const wordList&, bool)
    in file meshes/polyMesh/polyMeshFromShapeMesh.C at line 595
    Found 39800 undefined faces in mesh; adding to default patch.
Writing polyMesh
End

then i use this command to get patches :

autoPatch 80 -overwrite

i get the faces i need but once i reun checkMesh i get lots of errors about the mesh

Create time

--> FOAM Warning : 
    From function static Foam::instantList Foam::timeSelector::select0(Foam::Time&, const Foam::argList&)
    in file db/Time/timeSelector.C at line 274
    No time specified or available, selecting 'constant'
Create polyMesh for time = constant

Time = constant

Mesh stats
    points:           39800
    internal points:  0
    faces:            79003
    internal faces:   39203
    cells:            19701
    faces per cell:   6
    boundary patches: 5
    point zones:      0
    face zones:       0
    cell zones:       0

Overall number of cells of each type:
    hexahedra:     19701
    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               199      398      ok (non-closed singly connected)  
    auto1               19701    19900    ok (non-closed singly connected)  
    auto2               19701    19900    ok (non-closed singly connected)  
    auto3               199      398      ok (non-closed singly connected)  

Checking geometry...
    Overall domain bounding box (-2.49962617 -2.99990654 0) (3.5 2.99990654 1)
    Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
    Mesh has 3 solution (non-empty) directions (1 1 1)
    Boundary openness (0 -1.43760457e-17 -1.03426383e-15) OK.
 ***High aspect ratio cells found, Max aspect ratio: 3.914098022e+101, number of cells 19701
  <<Writing 19701 cells with high aspect ratio to set highAspectRatioCells
    Minimum face area = 7.004534805e-07. Maximum face area = 0.1461856339.  Face area magnitudes OK.
 ***Zero or negative cell volume detected.  Minimum negative volume: -0.01361617764, Number of negative volume cells: 19701
  <<Writing 19701 zero volume cells to set zeroVolumeCells
    Mesh non-orthogonality Max: 180 average: 168.9684194
 ***Number of non-orthogonality errors: 39203.
  <<Writing 39203 non-orthogonal faces to set nonOrthoFaces
 ***Error in face pyramids: 118206 faces are incorrectly oriented.
  <<Writing 79003 faces with incorrect orientation to set wrongOrientedFaces
    Max skewness = 1.450482967 OK.
    Coupled point location match (average 0) OK.

Failed 4 mesh checks.

End

Do you have any idea about why i get such bad quality mesh and how can i fix That? any idea would Help


Many Thanks

[Flowkersma]

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