[yangzo]

Hello everyone,

I am trying to use : mpirun -np 6 snappyHexMesh -overwrite -parallel
However, I get this error: --> FOAM FATAL ERROR: (openfoam-2312)
[2] cell 39973 of level 3 uses more than 8 points of equal or lower level
Points so far:8(16780 16925 25566 42788 43258 43259 64859 65157)

I tried the deleting everything except blockMesh under polymesh, it didn`t work.

Thanks in advance

[Yann]

Hello,

What are the exact steps you do? Have you re-run blockMesh?
If you used reconstructPar at some point, you should remove the constant/polyMesh folder. (and run blockMesh again to create your initial mesh)

Regards,
Yann

[yangzo]

Originally Posted by Yann

Hello,

What are the exact steps you do? Have you re-run blockMesh?
If you used reconstructPar at some point, you should remove the constant/polyMesh folder. (and run blockMesh again to create your initial mesh)

Regards,
Yann

Hello Yann,
Here are the steps I used:
blockMesh
surfaceFeatureExtract
decomposePar
mpirun -np 6 snappyHexMesh -overwrite -parallel
The first 3 steps works fine.
I deleted the polyMesh folder and "blockMesh" again but it didn`t solve the problem.

I am open for new suggestions

Cheers

[Yann]

The error you get means you try to run snappyHexMesh on a mesh which contains non hex cells. This usually happens when you re-run snappy on a mesh previously created by snappy (as snapping will split the cells overlapping the geometry surface).

Lets try to sum it up:

1. Remove processor* directories
2. Remove constant/polyMesh directory
3. Re-run the whole process (blockMesh, decomposePar, mpirun -np 6 snappyHexMesh -overwrite -parallel)

Make sure each steps runs fine (no errors on blockMesh or decomposePar)

[MMRC]

Hi, as Yan said this happens where there are no hex cells in the location where current snappy execution is trying to make changes. If you have run before snappy tool or refineHexMesh that may changed the shape of cells wheren your current snappy is now trying to make changes, this may be the reason of error