| mactone |
September 5, 2022 02:34 |
chekMesh is OK, but checkMesh with options indicates fails
Dear Formers,
I've constructed a burner flowfield geometry. After the blockMesh and snappyHexMesh, the mesh is generated successfully.
I've referenced the post checkMesh Ok but bad cells still present But no solution or explaination in that post. It seems use finer blockMesh is a solution?
My problem is pretty similar to that.
My questions is
1. Will this error has bad influence on my simulation such as bad convergence or bad accuracy due to the errors in the mesh?
2. How to refine the mesh so those errors can go away?
3. Why the checkMesh is okay, but checkMesh with furners options fails?
checkMesh, the output ends as follow, no error was shown:
Code:
Checking patch topology for multiply connected surfaces...
Patch Faces Points Surface topology
air 4804 5564 ok (non-closed singly connected)
fuel 1340 1544 ok (non-closed singly connected)
outlet 4104 4613 ok (non-closed singly connected)
wall_burner 81792 94012 ok (non-closed singly connected)
wall_chamber 109940 113596 ok (non-closed singly connected)
pilot 152 185 ok (non-closed singly connected)
Checking faceZone topology for multiply connected surfaces...
No faceZones found.
Checking basic cellZone addressing...
No cellZones found.
Checking geometry...
Overall domain bounding box (-0.4000000026 -0.4000000026 1.26361801e-08) (0.4000000026 0.4000000026 2.332000017)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (-1.120593655e-15 -1.21631218e-15 -7.792938171e-16) OK.
Max cell openness = 3.319599976e-16 OK.
Max aspect ratio = 6.429704674 OK.
Minimum face area = 3.978369824e-08. Maximum face area = 0.0001908707779. Face area magnitudes OK.
Min volume = 5.927097015e-11. Max volume = 2.604615265e-06. Total volume = 0.799458194. Cell volumes OK.
Mesh non-orthogonality Max: 54.97320245 average: 7.136477232
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 2.85596137 OK.
Coupled point location match (average 0) OK.
Mesh OK.
End
But, when I
checkMesh --allTopology --allRegions, the same mesh has errors as follow
Code:
Checking faceZone topology for multiply connected surfaces...
No faceZones found.
Checking basic cellZone addressing...
No cellZones found.
Checking geometry...
Overall domain bounding box (-0.4000000026 -0.4000000026 1.26361801e-08) (0.4000000026 0.4000000026 2.332000017)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (-1.120593655e-15 -1.21631218e-15 -7.792938171e-16) OK.
Max cell openness = 3.319599976e-16 OK.
Max aspect ratio = 6.429704674 OK.
Minimum face area = 3.978369824e-08. Maximum face area = 0.0001908707779. Face area magnitudes OK.
Min volume = 5.927097015e-11. Max volume = 2.604615265e-06. Total volume = 0.799458194. Cell volumes OK.
Mesh non-orthogonality Max: 54.97320245 average: 7.136477232
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 2.85596137 OK.
Coupled point location match (average 0) OK.
***Error in face tets: 344 faces with low quality or negative volume decomposition tets.
<<Writing 336 faces with low quality or negative volume decomposition tets to set lowQualityTetFaces
Min/max edge length = 5.657329348e-05 0.01392850623 OK.
*There are 2166 faces with concave angles between consecutive edges. Max concave angle = 72.7399196 degrees.
<<Writing 2166 faces with concave angles to set concaveFaces
Face flatness (1 = flat, 0 = butterfly) : min = 0.4816127466 average = 0.9996852552
*There are 10 faces with ratio between projected and actual area < 0.8
Minimum ratio (minimum flatness, maximum warpage) = 0.4816127466
<<Writing 10 warped faces to set warpedFaces
Cell determinant (wellposedness) : minimum: 0.01350136115 average: 1.474873198
Cell determinant check OK.
***Concave cells (using face planes) found, number of cells: 38934
<<Writing 38934 concave cells to set concaveCells
Face interpolation weight : minimum: 0.1164988534 average: 0.4833431086
Face interpolation weight check OK.
Face volume ratio : minimum: 0.02502027251 average: 0.9134506808
Face volume ratio check OK.
Failed 2 mesh checks.
Writing fields with mesh quality parameters
Writing non-orthogonality (angle) to nonOrthoAngle
Writing face interpolation weights (0..0.5) to faceWeight
Writing face skewness to skewness
Writing cell determinant to cellDeterminant
Writing aspect ratio to aspectRatio
Writing approximate aspect ratio to cellAspectRatio
Writing cell shape (hex, tet etc.) to cellShapes
Writing cell volume to cellVolume
Writing cell volume ratio to cellVolumeRatio
Writing minTetVolume to minTetVolume
Writing minPyrVolume to minPyrVolume
Writing cell region to cellRegion
Writing cell zoning to cellZone
Writing face zoning to faceZone
End
Failed 2 mesh checks which are
***Error in face tets: 344 faces with low quality or negative volume decomposition tets.
***Concave cells (using face planes) found, number of cells: 38934 |
