SimScale CAE Forum

Illegal cells inspection and Treatment


#1

I need to inspect bad cells in a mesh, to find out which geometry is causing problems.
From the meshing log:
Checking final mesh …
Checking faces in error :
non-orthogonality > 75 degrees : 3092
faces with face pyramid volume < 1e-13 : 0
faces with concavity > 80 degrees : 2
faces with skewness > 4 (internal) or 20 (boundary) : 0
faces with interpolation weights (0…1) < 0.01 : 3
faces with volume ratio of neighbour cells < 0.0075 : 19
faces with face twist < 0.005 : 182
faces on cells with determinant < 0.005 : 0
Finished meshing with 3298 illegal faces (concave, zero area or negative cell pyramid volume)
Finished meshing in = 5809 s.
End
Is there a recommended procedure to dealing with each of these type of illegal cells?


Meshing problem: To many illegal faces
Stirred reactor simulation - unsatisfying results
#2

Hi @Naly,

could you share the project with us?

If you do not know how to do it, please see: How to share a project

Cheers!

Jousef


#3

@jousefm Thanks a lot for offering to help.I managed to decrease the illegal cell count to about 300 by changing these mesh controls
Minimum angle for feature detection [°] to 1
Max face angle for layer generation [°] to 180
Min angle between patches for layers [°] to 1
And down to 0 illegal cells by changing:
Mesh-to-geometry conformation iterations to 1
Max iterations for mesh conformation to 1


CFD FSAE Project - Yaw Study Simulation Error