ListGetInteger error in Periodic BC

[denis.cohen]

Hello,

I am getting an error in the sif file which I can't figure out:
ERROR:: ListGetInteger: Given value 7 for property: [Periodic BC] larger than given maximum: 5

However my mesh.boundary contains 16 boundaries so more than 5.

Here is the periodic bc from my sif file.

Code: Select all

Boundary Condition 5
   Name = "Periodic"
   Target Boundaries = 11
   Periodic BC = 7
   Periodic BC Rotate(3) = 0.0 0.0 $3.141592654/6.
   Periodic BC Velocity 1 = Logical True
   Periodic BC Velocity 2 = Logical True
   Periodic BC Velocity 3 = Logical True
   Periodic BC Pressure = Logical True
End

Any help appreciated.
Thank you.

Denis Cohen

[raback]

Hi

Note that the index of "Periodic BC" refers to the i in the "Boundary Condition i" declaration. Only if your "Target Boundaries = i" for all i, are these the same. Often there are less BCs than there are Target Boundaries.

-Peter

[denis.cohen]

Hi Peter,

I am confused because I thought there is no relation between the i of
Boundary Condition i
and the assignment of a number to the keywords Target Boundaries and Periodic BC. I am now at a loss of how to do it.
My mesh.boundary contains 16 boundaries of which there is an inlet (Boundary 11) and an outlet (Boundary 7). The problem is periodic so outlet = inlet for velocity and pressure. In my .sif file I define 4 types of BC (modified from my previous email but error persists). Here is the part of the sif file:

Code: Select all

!---------------------------------------------------
!---------------- BOUNDARY CONDITIONS --------------
!---------------------------------------------------
Boundary Condition 1
   Name = "Bottom"
   Target Boundaries(3) = 1 2 3
   Velocity 1 = Real 0.0
   Velocity 2 = Real 0.0
   Velocity 3 = Real 0.0
!  Flux Integrate = Logical True
End

!---------------------------------------------------

Boundary Condition 2
  Name = "Top"
  Target Boundaries(3) = 4 5 6
  Velocity 1 = Variable Coordinate
     Real MATC "vtheta(0.0) * sqrt(pow(tx(0),2) + pow(tx(1),2)) * (-sin(atan(tx(1)/tx(0))))"
  Velocity 2 = Variable Coordinate
     Real MATC "vtheta(0.0) * sqrt(pow(tx(0),2) + pow(tx(1),2)) * (cos(atan(tx(1)/tx(0))))"
  Velocity 3 = Real 0.0
End

!---------------------------------------------------

Boundary Condition 3
  Name = "Inner-Outer Walls"
  Target Boundaries(6) = 8 9 10 12 13 14
  Normal-Tangential Velocity = Logical True
  Velocity 1 = Real 0.0
End

!---------------------------------------------------

Boundary Condition 4
   Name = "Periodic"
   Target Boundaries = 11
   Periodic BC = 7
   Periodic BC Rotate(3) = 0.0 0.0 $3.141592654/6.
   Periodic BC Velocity 1 = Logical True
   Periodic BC Velocity 2 = Logical True
   Periodic BC Velocity 3 = Logical True
   Periodic BC Pressure = Logical True
End

I don't know what is not working here. Thanks for your help.

Denis

[raback]

Hi

So you don't have any BC for the periodic outlet currently. You should add

Code: Select all

Boundary Condition 5
   Name = "Periodic_Counterpart"
   Target Boundaries = 7
End


And then set the "Periodic BC= 5" correspondingly.

-Peter

[denis.cohen]

Hi Peter,

OK this seems to have fixed it. I am now getting a WARNING that suggests something is still wrong.

here the part of my sif with the inlet/outlet periodic bc:

Code: Select all

!---------------------------------------------------

Boundary Condition 4
   Name = "Inlet"
   Target Boundaries = 5
End

!---------------------------------------------------

Boundary Condition 5
   Name = "Outlet"
   Target Boundaries = 8
   Periodic BC = 5
   Periodic BC Rotate(3) = 0.0 0.0 -$acos(-1.0)/6.
   Periodic BC Velocity 1 = Logical True
   Periodic BC Velocity 2 = Logical True
   Periodic BC Velocity 3 = Logical True
   Periodic BC Pressure = Logical True
End

I get this WARNING

Code: Select all

PeriodicProjector: Starting to build
WARNING:: PeriodicProjector: Nodes belonging to both Master and Target: 1239
PeriodicProjector: Suggested angle between two normals in degs:    0.000E+00
PeriodicProjector: Number of periodic nodes: 1320, 1320
PeriodicProjector: Rotating target with:    0.000E+00   0.000E+00  -5.236E-01
PeriodicProjector: Master normal:   -4.540E-01   8.910E-01   0.000E+00
PeriodicProjector: Initial Target normal:   -4.540E-01   8.910E-01   0.000E+00
PeriodicProjector: Rotated Target normal:   -4.458E-01   8.951E-01   0.000E+00
PeriodicProjector: Angle between Master and initial Target:  0.00000E+00
PeriodicProjector: Angle between Master and rotated Target:  5.23599E-01
WARNING:: PeriodicProjector: Rotation may be incorrect!
PeriodicProjector: Minimum values for this periodic BC:     2.228E-01   1.135E-01   1.741E-02
PeriodicProjector: Minimum values for target periodic BC:   2.228E-01   1.135E-01   1.741E-02
PeriodicProjector: Minimum values for rotated target:       2.238E-01   1.115E-01   1.741E-02
PeriodicProjector: Maximum values for this periodic BC:     4.010E-01   2.043E-01   2.400E-01
PeriodicProjector: Maximum values for target periodic BC:   4.010E-01   2.043E-01   2.400E-01
PeriodicProjector: Maximum values for rotated target:       4.028E-01   2.006E-01   2.400E-01
PeriodicProjector: Bounding box for this periodic BC:     1.782E-01   9.080E-02   2.226E-01
PeriodicProjector: Bounding box for target periodic BC:   1.782E-01   9.080E-02   2.226E-01
PeriodicProjector: Bounding box for rotated target:       1.790E-01   8.917E-02   2.226E-01
PeriodicProjector: Scaling with:    1.000E+00   1.000E+00   1.000E+00
PeriodicProjector: Translation:   -1.028E-03   2.040E-03   3.469E-18
BuildQuandrantTree: Start
BuildQuandrantTree: Ready
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!           1
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!           3
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!           4
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!           5
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!           6
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!           7
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!           8
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!           9
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!          10
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!          11
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!          12
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!          13
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!          14
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!          15
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!          16
WARNING:: InterpolateMeshToMesh:  Point was not found in any of the elements!          17
WARNING:: GlobalToLocal: did not converge.
rst  2.73667599485800686E-020 -1.07155289217097487E-020 -6.93889390390722838E-018  2.22044604925031308E-016
err          51  1.77432542772708389E-006  2.22044604925031308E-016  1.49011611938476563E-008
delta  3.84653583449562871E-015 -2.13348013301076425E-014   0.0000000000000000
prevdelta  1.86072364586724714E-014  1.91508223610561327E-014   0.0000000000000000

...

The outlet position is obtained from the inlet by a rotation of +pi/6 along the z-axis. I thought that this would do it:
Periodic BC Rotate(3) = 0.0 0.0 -$acos(-1.0)/6.
Trying with a + kept the WARNING.

Am I misunderstanding the Rotation?

Thanks

Denis

[raback]

Hi Denis

After the coordinate transformation the two BCs should be on top of each other. Now it seems close but not accurate enough. Can you increase the accuracy by some means, or do you think that they should be accurate as is?

-Peter

[denis.cohen]

Hi Peter,
I don't know why the boundaries are not on top. I am using gmsh to make the 2d mesh, then ExtrudeMesh to create the 3d.

But anyway I think it should be accurate as is. Should I do something to suppress the warnings?

Also should the rotation in the Periodic BC be from the Target Boundary to the Periodic BC or vice versa?

Thanks for your help.

Denis

[raback]

Hi Denis

Your case seems close enough so that I suspect the angle of rotation is correct. Do you have problems with all the nodes, or just with some subset?

-Peter

[denis.cohen]

Hi Peter,

I think it's all the nodes of the periodic The periodic bc should have 1320 nodes. I only get 1277 lines with this WARNING:

WARNING:: InterpolateMeshToMesh: Point was not found in any of the elements! 1031

The remaining nodes are likely the Dirichlet nodes.

I am also not getting a good flow solution. Could that be due to Elmer not finding the nodes? It could also be that I have some errors in my sif file.

Thanks

Denis

[raback]

Hi

If Elmer does not find the nodes then it cannot make the periodic system happen.

Perhaps you could define a small case for inspection.

-Peter