CFD Online Discussion Forums - [gmshToFoam] [checkMesh] Error high aspect ratio, ngetaive face area and cell volume

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)

- Mesh Generation & Pre-Processing (https://www.cfd-online.com/Forums/mesh-generation/)

- - [gmshToFoam] [checkMesh] Error high aspect ratio, ngetaive face area and cell volume (https://www.cfd-online.com/Forums/mesh-generation/234980-gmshtofoam-checkmesh-error-high-aspect-ratio-ngetaive-face-area-cell-volume.html)

[gmshToFoam] [checkMesh] Error high aspect ratio, ngetaive face area and cell volume

Hello forum !

First of all I am new to Openfoam. I have a mesh using GMSH, extrude (to get 3D domain) and gmshToFoam. At first, its all looks nice until i do « checkMesh » and all of enjoyment dissapear. I have this following error

Code:

 ***High aspect ratio cells found, Max aspect ratio: 3.35195e+155, number of cells 67

  <<Writing 67 cells with high aspect ratio to set highAspectRatioCells

 ***Zero or negative face area detected.  Minimum area: 0

  <<Writing 137 zero area faces to set zeroAreaFaces

 ***Zero or negative cell volume detected.  Minimum negative volume: 0, Number of negative volume cells: 67

  <<Writing 67 zero volume cells to set zeroVolumeCells

    Mesh non-orthogonality Max: 90 average: 34.0927

 ***Number of non-orthogonality errors: 37.

  <<Writing 37 non-orthogonal faces to set nonOrthoFaces

    Face pyramids OK.

 ***Max skewness = 1.78771e+154, 135 highly skew faces detected which may impair the quality of the results

  <<Writing 135 skew faces to set skewFaces

    Coupled point location match (average 0) OK.



Failed 5 mesh checks.



End

There is no way I can get a ratio that high since I dont have that much distance in my domain. Somehelp might be usefull to me, thanks !!

I've recently had a similar issue and found that GMSH's Transfinite meshing with grading (for boundary layers, for example) caused such non-realistic results in checkMesh (by removing the grading checkMesh was happy).

If needing grading, perhaps use GMSH's boundaryLayer (Field) method. Details on the code needed: https://www.cfd-online.com/Forums/ma...ayer-gmsh.html