[2538sukham]

The geometry is of a cylinder with an outlet where the piston wall moves according to a given acceleration. The simulation doesnt crash. However the interface is smeared completely on the curved side when the time goes beyond 1.3s . Can numerics in the fvScheme and fvSolutions solve this? I tried first order accurate numerics but the problem persist. Hope someone could shed a light on the matter. The dynamic mesh strategy is layer addition/removal which is basically the same as linearValveLayersFvMesh but without the sliding and attach/dettach. I have a feeling it is the layer removal that is causing the issue here. I tried 2D simulations which worked fine with Co limited to 0.5.

[2538sukham]

I will see if slip boundary condition on the curved wall can solve the issue. I will update it once it is done. It is a laminar case and the mesh qualify is quite fine.
With regards

Time = 0

Mesh stats
points: 250971
faces: 723747
internal faces: 686931
cells: 236596
faces per cell: 5.962391587
boundary patches: 6
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 227698
prisms: 8886
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 0
polyhedra: 12
Breakdown of polyhedra by number of faces:
faces number of cells
5 12

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
movingWall 644 681 ok (non-closed singly connected)
axisymmetricWall 14808 15227 ok (non-closed singly connected)
endWall 644 681 ok (non-closed singly connected)
outlet 74 86 ok (non-closed singly connected)
outletWall 224 266 ok (non-closed singly connected)
slipWall 20422 20852 ok (non-closed singly connected)

Checking geometry...
Overall domain bounding box (-2.820619714e-18 -1.220390009e-05 -0.02539999969) (0.4571999907 0.02539999929 0.03999999911)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (-1.640392498e-17 -4.077182065e-14 2.856011275e-16) OK.
Max cell openness = 3.306403551e-16 OK.
Max aspect ratio = 3.738211928 OK.
Minimum face area = 5.254412515e-07. Maximum face area = 2.822238269e-06. Face area magnitudes OK.
Min volume = 4.946108036e-10. Max volume = 3.017000178e-09. Total volume = 0.0004643142593. Cell volumes OK.
Mesh non-orthogonality Max: 54.42242443 average: 2.448434327
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 0.6262472254 OK.
Coupled point location match (average 0) OK.

Mesh OK.

End

[2538sukham]

Well slip BC doesnt have much differences. Checking with interface compression cAlpha 0 to see if the problem is in the compression. If this fails, I think I will be lost in words .

[2538sukham]

Well when cAlpha is 0 i.e. without interface compression the flow is fine but its too diffusive. The image is attached. For now, I am producing the result from paraFoam -nativeReader with contour of alpha1 0.5. It is comparable to Aboudi et.al 2011 for high pressure die casting. Interface compression with topologically removing cells results in wiggles at the interface. Without the interface compression it is too much smeared. I don't know if CLSVOF which couples level set with classical VoF will be helpful in getting sharp interface. Any one can shed some light on this matter. I will try 0.5 cAlpha and see if the wiggles still persist.

[2538sukham]

I am still lost. The fluid interface is wiggling near the top end of the cylinder. smoothing the mesh might be the solution but it will be in the expense of the mesh being too fine. Geometrical reconstruction might be the solution but with topo change, it seems quite a challenging task.

[2538sukham]

Found that WRAFTS code and flow3D is mainly used for high pressure die casting and shot sleeve wave dynamics. Is this something which will be really difficult in OpenFOAM?? All suggestions are welcomed