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Old   July 12, 2017, 04:19
Default Problem in running coarse mesh(on the other hand fine mesh is running)
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Ashok
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Good Morning,

Recently I encountered a Problem. I have created 2 different cases with only difference in mesh(one is fine mesh and other is coarse), the rest of settings are undisturbed. Inspite of all the settings being same except mesh, coarse mesh case is not running but fine mesh case is running successfully. The tar files are attached below for both the cases.

Someone please kindly help me to sort out were the Problem is.
Attached Files
File Type: gz case_coarse.tar.gz (5.8 KB, 2 views)
File Type: gz case_fine.tar.gz (5.8 KB, 1 views)
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Old   July 12, 2017, 04:32
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Would you please specify a little more information?

What does "not running" mean?
Does that mean the case crashes at the very first timestep, or that the case hits a FPE after some time, or ...?
If such a crash does indeed happen, you should post the last ~3 timesteps of your log file.
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Old   July 12, 2017, 04:35
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You should also post checkMesh output for both meshes.
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Old   July 12, 2017, 05:00
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Not running means, getting error like

--> FOAM FATAL ERROR:
Continuity error cannot be removed by adjusting the outflow.
Please check the velocity boundary conditions and/or run potentialFoam to initialise the outflow.
Total flux : 1e-300
Specified mass inflow : 1.6802e-20
Specified mass outflow : 1.83295e-20
Adjustable mass outflow : 0

Once after running interFoam I gets error message as above only in case of coarse mesh but fine mesh case runs fine.
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Old   July 12, 2017, 05:03
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checkMesh- coarse Mesh case

Create time

Create polyMesh for time = 0

Time = 0

Mesh stats
points: 16151
faces: 46100
internal faces: 43900
cells: 15000
faces per cell: 6
boundary patches: 3
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 15000
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
bottomWall 500 521 ok (non-closed singly connected)
atmosphere 500 521 ok (non-closed singly connected)
movingWall 1200 1240 ok (non-closed singly connected)

Checking geometry...
Overall domain bounding box (-0.063 0 -0.063) (0.063 0.5 0.063)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (2.35058e-17 1.72541e-16 -3.47107e-18) OK.
Max cell openness = 2.36956e-16 OK.
Max aspect ratio = 11.8005 OK.
Minimum face area = 1.07407e-05. Maximum face area = 0.000164764. Face area magnitudes OK.
Min volume = 1.79012e-07. Max volume = 6.615e-07. Total volume = 0.00620888. Cell volumes OK.
Mesh non-orthogonality Max: 31.7106 average: 6.63087
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 2.2423 OK.
Coupled point location match (average 0) OK.

Mesh OK.

End

CheckMesh- fineMesh

Create time

Create polyMesh for time = 0

Time = 0

Mesh stats
points: 104091
faces: 304000
internal faces: 296000
cells: 100000
faces per cell: 6
boundary patches: 3
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 100000
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
bottomWall 2000 2041 ok (non-closed singly connected)
atmosphere 2000 2041 ok (non-closed singly connected)
movingWall 4000 4080 ok (non-closed singly connected)

Checking geometry...
Overall domain bounding box (-0.063 0 -0.063) (0.063 0.5 0.063)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (4.71457e-17 6.07412e-16 1.49041e-17) OK.
Max cell openness = 2.41381e-16 OK.
Max aspect ratio = 15.9624 OK.
Minimum face area = 2.38208e-06. Maximum face area = 4.94674e-05. Face area magnitudes OK.
Min volume = 2.38208e-08. Max volume = 9.9225e-08. Total volume = 0.00622808. Cell volumes OK.
Mesh non-orthogonality Max: 37.9828 average: 7.25481
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 2.36114 OK.
Coupled point location match (average 0) OK.

Mesh OK.

End


In case of much more information, Im happy to share. Thank you
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Old   July 13, 2017, 03:35
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Quote:
Originally Posted by floquation View Post
Would you please specify a little more information?

What does "not running" mean?
Does that mean the case crashes at the very first timestep, or that the case hits a FPE after some time, or ...?
If such a crash does indeed happen, you should post the last ~3 timesteps of your log file.
Thank you for your Response. I mean the code gives an error as stated below

--> FOAM FATAL ERROR:
Continuity error cannot be removed by adjusting the outflow.
Please check the velocity boundary conditions and/or run potentialFoam to initialise the outflow.
Total flux : 1e-300
Specified mass inflow : 1.6802e-20
Specified mass outflow : 1.83295e-20
Adjustable mass outflow : 0

Once after running interFoam I gets error message as above only in case of coarse mesh but fine mesh case runs fine.
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Old   July 13, 2017, 03:36
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Quote:
Originally Posted by BlnPhoenix View Post
You should also post checkMesh output for both meshes.
checkMesh- coarse Mesh case

Create time

Create polyMesh for time = 0

Time = 0

Mesh stats
points: 16151
faces: 46100
internal faces: 43900
cells: 15000
faces per cell: 6
boundary patches: 3
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 15000
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
bottomWall 500 521 ok (non-closed singly connected)
atmosphere 500 521 ok (non-closed singly connected)
movingWall 1200 1240 ok (non-closed singly connected)

Checking geometry...
Overall domain bounding box (-0.063 0 -0.063) (0.063 0.5 0.063)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (2.35058e-17 1.72541e-16 -3.47107e-18) OK.
Max cell openness = 2.36956e-16 OK.
Max aspect ratio = 11.8005 OK.
Minimum face area = 1.07407e-05. Maximum face area = 0.000164764. Face area magnitudes OK.
Min volume = 1.79012e-07. Max volume = 6.615e-07. Total volume = 0.00620888. Cell volumes OK.
Mesh non-orthogonality Max: 31.7106 average: 6.63087
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 2.2423 OK.
Coupled point location match (average 0) OK.

Mesh OK.

End

CheckMesh- fineMesh

Create time

Create polyMesh for time = 0

Time = 0

Mesh stats
points: 104091
faces: 304000
internal faces: 296000
cells: 100000
faces per cell: 6
boundary patches: 3
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 100000
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
bottomWall 2000 2041 ok (non-closed singly connected)
atmosphere 2000 2041 ok (non-closed singly connected)
movingWall 4000 4080 ok (non-closed singly connected)

Checking geometry...
Overall domain bounding box (-0.063 0 -0.063) (0.063 0.5 0.063)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (4.71457e-17 6.07412e-16 1.49041e-17) OK.
Max cell openness = 2.41381e-16 OK.
Max aspect ratio = 15.9624 OK.
Minimum face area = 2.38208e-06. Maximum face area = 4.94674e-05. Face area magnitudes OK.
Min volume = 2.38208e-08. Max volume = 9.9225e-08. Total volume = 0.00622808. Cell volumes OK.
Mesh non-orthogonality Max: 37.9828 average: 7.25481
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 2.36114 OK.
Coupled point location match (average 0) OK.

Mesh OK.

End


In case of much more information, Im happy to share. Thank you
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Old   July 17, 2017, 04:56
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Ashok
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Hello, am still waiting for the Reply. Any sort of help is appreciated. Thanks in advance
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