Conjugate heat transfert - 2D - Flow past cylinder

[jgd23]

Hello Yvan,

I use the group name "interface_fs" which I have defined in Salome.
This interface is the internal fluid/solid interface of the original mesh.
I don't have files in the SRC folder.

I have attached MED file exported from Mesh.

Thank you for your help.

Best regards

[jgd23]

I try to have 2 meshes and join them.

The result is the same. I think that I don't know how to declare the interface again.

In the joining sub-menu I choose the 2 BC defined in Salome named "interface_fs" and "interface_sf" respectively the fluid/solid interface (boundary of the fluid volume) and the solid/fluid interface (boundary of the solid volume).

CS doesn't recognize these boundaries "interface_fs" and "interface_sf", I think that the joining operation failed.
The coupling is the solver.log = 0

The standard computation fails at the same stage than the cases before.

See the solver.log.file

Best regards

[Antech]

Maybe I'm wrong but I think it's suspecious that Saturne complains on interface named selections. I used fluid-fluid coupling with non-conformal meshes and calculation was OK. Here is my joining log:

Code: Select all

Joining number 1:

  Selection criteria: "IFC_CELL_AIR_FRONT_1 OR IFC_AIR_CELL_FRONT_1"

  Parameters for the joining operation:
    Shortest incident edge fraction:           0.10000
    Maximum angle between joined face planes: 25.00000

  Advanced joining parameters:
    Verbosity level:                                 1
    Visualization level:                             1
    Deepest level reachable in tree building:       30
    Max boxes by leaf:                              25
    Max ratio of linked boxes / init. boxes:   5.00000
    Max ratio of boxes for distribution:       2.00000
    Merge step tolerance multiplier:           1.00000
    Pre-merge factor:                          0.05000
    Tolerance computation mode:                      1
    Intersection computation mode:                   1
    Max. number of equiv. breaks:                  500
    Max. number of subfaces by face:               200

  Before joining
     Number of cells:          4990095
     Number of interior faces: 10022384
     Number of boundary faces: 201992
     Number of vertices:       985348

  Global number of boundary faces selected for joining:       6390

  Element selection successfully done.
  Global min/max. tolerance:

 Glob. Num. |  Tolerance  |              Coordinates

      13747 |    0.008580 |  7.4279999733e+00   1.9880037308e+00   8.1232559681e-01 | ORI
     407141 |    0.022246 |  7.4279999733e+00   4.7711644173e+00   1.4988535643e+00 | ORI
  Determination of possible face intersections:

    bounding-box tree layout: 2D

  Global number of intersections detected:        46627
    Vertex-Vertex intersections:            1701
    Other intersections:                   44926

  Joining operation is non-conforming.

  Global number of new vertices to create:      22377

  Equivalences broken for 3 edges.

  Edge intersections and vertex creation done.

  Pre-merge for 84303 global element couples.

  Max size of a merge set of vertices: 9

  Excessive transitivity for 0 set(s) of vertices.

  Edge removed for 237 faces (global).
  Join mesh cleaning done.

  Edge removed for 44 faces (global).
  Join mesh cleaning done.

  Merge vertices and mesh update done.

  Global number of faces after splitting:      13568

  Global configuration after the joining operation:
     Global number of border faces to add:          0

  Mesh cleaning done for degenerate faces.
    Global number of cleaned interior faces:        0
    Global number of cleaned border faces:          0

  After joining
     Number of cells:          4990095
     Number of interior faces: 10035952
     Number of boundary faces: 195602
     Number of vertices:       991721


  Joining  1 completed (1.99 s).

As you can see, selection criteria in log is "IFC_CELL_AIR_FRONT_1 OR IFC_AIR_CELL_FRONT_1", in Saturne GUI it's without any quotes. In your log, there are extra-quotes and "," instead of OR. Maybe try with joining criteria interface_fs OR interface_sf ? Although, according to log, 63 faces are selected for joining. Maybe the problem related particulary to internal coupling...

Boundaries themselves are recognized correctly:

Code: Select all

  Boundary zone "interface_fs"
    id              = 2
    Number of faces = 63
    Surface         = 0.0015701
    Center of gravity = (4.3157e-18, -0.0025, 3.2368e-18)
    Perimeter       = -1 (not computed)
  Boundary zone "interface_sl"
    id              = 7
    Number of faces = 63
    Surface         = 0.0015701
    Center of gravity = (-4.3157e-18, -0.0025, 0)
    Perimeter       = -1 (not computed)

63 faces are selected for each of interface sides.

I never used internal coupling in Saturne (we usually use CFX for such cases because of auto-interface feature), but I'm potentially interested in Saturne conjugated heat transfer too.

[jgd23]

Hello,

With the syntax 'interface_fs' OR 'interface_sf' or without the punctuation interface_fs OR interface_sf
gives exactly the same result.

Maybe my boundary declaration is not appropriate, I have 2 boundaries for the interface solid/ fluid?

Maybe someone has already define a simple case of CHT with CS where I can check everything compare to my case?

Best regards

[Antech]

Thanks for your response. I have 2 BCs also, it's not an internal boundary and it's not a conformal mesh. The difference is that there is a fluid/fluid interface in my case. Will wait what Ivan says...

[Yvan Fournier]

Hello,

Yes, the issue in you log is here:

Code_Saturne: /home/julien/Code_Saturne/code_saturne-7.2.0/src/base/cs_selector.c:111: Warning
The group "interface_sf" in the selection criteria:
"'interface_fs','interface_sf'"
does not correspond to any boundary face.
Global number of boundary faces selected for joining: 63

Because the selection criteria syntax seems wrong or not working.

Actually, I need to check if the "," alternative to "or" in selection criteria really works (it seems it may not; it should in theory, but most of the time, "or" is used instead, so it is not tested much).

Can you try using:

"interface_fs or interface_sl"

As a selection criteria (no quotes needed if done in the GUI).

Best regards,

Yvan

[jgd23]

Hello,

With the join definition syntax:
interface_fs or interface_sl

the join is done but a new problem appears.
Again with some interface definition, see the solver log file

Best regards

[jgd23]

If I remove from the list of BC one of the two interface BC.

I have a new error message about wall distance.

[jgd23]

Hello,

Here is the 2 meshes of the fluid and solid parts if someone wants to try the joining and coupling.

Best regards