| Zbynek |
February 10, 2017 07:34 |
Polyhedra - cells with multiple inbetween faces
Dear all,
I converted a Fluent 3-D hex/polyhedral mesh using the fluent3DMeshToFoam utility. The domain has a rotational part and a stationary part with interfaces between them. I am using OF 3.0.1. The conversion itself runs fine. However, when I use checkMesh, I get the following output (abbreviated):
Code:
Checking topology...
Boundary definition OK.
Cell to face addressing OK.
Point usage OK.
<<Found 32 neighbouring cells with multiple inbetween faces.
Upper triangular ordering OK.
<<Writing 64 unordered faces to set upperTriangularFace
Face vertices OK.
*Number of regions: 2
The mesh has multiple regions which are not connected by any face.
<<Writing region information to "0/cellToRegion"
<<Writing region 0 with 647222 cells to cellSet region0
<<Writing region 1 with 785034 cells to cellSet region1
Checking patch topology for multiply connected surfaces...
Patch Faces Points Surface topology
ns_wall 27528 27676 ok (non-closed singly connected)
ns_impeller-ns_stationary 2220 2368 ok (non-closed singly connected)
ns_impeller-ns_rotational 31220 52564 ok (non-closed singly connected)
ns_baffles 12712 12784 ok (non-closed singly connected)
ns_surface 7669 7808 ok (non-closed singly connected)
AMI1 23686 46822 ok (non-closed singly connected)
AMI2 18241 18316 ok (non-closed singly connected)
Checking geometry...
Overall domain bounding box (-0.689845 -0.298263 -0.689845) (0.689845 1.13 0.689845)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (-9.01689e-17 4.19045e-16 3.36408e-16) OK.
Max cell openness = 3.04687e-16 OK.
Max aspect ratio = 18.8908 OK.
Minimum face area = 4.62885e-08. Maximum face area = 0.000518877. Face area magnitudes OK.
Min volume = 1.44049e-09. Max volume = 4.69178e-06. Total volume = 1.98718. Cell volumes OK.
Mesh non-orthogonality Max: 50.5215 average: 9.01362
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 1.45756 OK.
Coupled point location match (average 0) OK.
Mesh OK.
As you can see, the mesh is of a good quality, there is no problem. What bothers me are the two lines "Found 32 neighbouring cells with multiple inbetween faces" and "Writing 64 unordered faces to set upperTriangularFace". I did not manage to find any satisfactory explanation what these lines mean and what impact they could have on the solution.
I should say that I ran a couple of simulation using MRF (simpleFoam) as well as moving mesh (pimpleDyMFoam) and all the results seem to be all right. So really, there is maybe no need to worry about it but it would be great if someone could shed some more light on the meaning of the lines.
Any input would be appreciated.
Best,
Zbynek |
