ChtMultiRegionFoam : pressure oscillating using a t junction geometry
 

Hello Foamers,

I'm trying to model a T-junction with conjugate heat transfer. The objective being able to run an LES simulation for a certain amount of time, I would like to initialize this case from a RANS computation.
I've been able to run an equivalent of this case in FLUENT with a comparable mesh but I cannot reproduce the same convergence behavior in OpenFOAM.

I tried switching from 2nd order to schemes to 1st order, testing different limiters as well as different linear solvers (GAMG/PCG) for pressure. I also used temperature Limits.

In every configuration tested, the residuals for pressure keep oscillating as in the picture.

Here is the result of checkMesh

Mesh stats
points: 680510
faces: 2013016
internal faces: 1985360
cells: 666396
faces per cell: 6
boundary patches: 4
point zones: 0
face zones: 0
cell zones: 2

Overall number of cells of each type:
hexahedra: 666396
prisms: 0
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 0
polyhedra: 0

Checking topology...
Boundary definition OK.
Cell to face addressing OK.
Point usage OK.
Upper triangular ordering OK.
Face vertices OK.
Number of regions: 1 (OK).

Checking patch topology for multiply connected surfaces...
Patch Faces Points Surface topology
inlet 1424 1463 ok (non-closed singly connected)
outlet 1424 1463 ok (non-closed singly connected)
solid_wall 23476 23587 ok (non-closed singly connected)
top 1332 1369 ok (non-closed singly connected)

Checking faceZone topology for multiply connected surfaces...
No faceZones found.

Checking basic cellZone addressing...
CellZone Cells Points Volume BoundingBox
fluid 381636 394196 0.033184772 (0 -0.07 -0.07) (2 0.38 0.07)
solid 284760 306765 0.0071225423 (0 -0.077 -0.077) (2 0.38 0.077)

Checking basic pointZone addressing...
No pointZones found.

Checking geometry...
Overall domain bounding box (0 -0.077 -0.077) (2 0.38 0.077)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (1.1900187e-17 1.4072246e-15 -2.9427474e-17) OK.
Max cell openness = 6.3700008e-16 OK.
Max aspect ratio = 100.73856 OK.
Minimum face area = 7.9176419e-07. Maximum face area = 0.00034169823. Face area magnitudes OK.
Min volume = 3.28995e-09. Max volume = 2.2391697e-06. Total volume = 0.040307315. Cell volumes OK.
Mesh non-orthogonality Max: 62.619621 average: 21.328153
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 1.9596531 OK.
Coupled point location match (average 0) OK.

Mesh OK.

End

If you want to test it on your side, the test case is available here: https://drive.google.com/file/d/1g3q...ew?usp=sharing

Any idea ?

Thank you in advance,