BC for infinite longe wire

Numerical methods and mathematical models of Elmer
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Bavragor
Posts: 32
Joined: 07 Nov 2013, 14:10
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BC for infinite longe wire

Post by Bavragor »

Hi,

At the moment I try to create some simple cases for myself to get into Elmer electromagnetic simulation. At the moment I have a problem with the boundary condition for an infinite long wire. My model consists of 4 cylinders/hollow cylinders. In the middle the wire, than air, electrical steel (at the moment with const. rel. permeability) and again air as last material (picture).
hidden surfaces (air) for better overview
hidden surfaces (air) for better overview
model.png (151.23 KiB) Viewed 1177 times
In my understanding the bc in z-driection have to be Magnetic Flux Density 3 = Real 0.
The results with different bc:

1. Magnetic Flux Density 3 = Real 0 at every face in z-direction (also at the two ends of the wire)
-->WhitneyAVSolver ends with:
Program received signal SIGSEGV: Segmentation fault - invalid memory reference.

Backtrace for this error:
#0 ffffffffffffffff
2. Same error for other bc like Magnetic Flux Density 3 = Real 0 at every face in z-direction instead of the faces for the wire. But at first there wasn't this error but the solution of statcurrent or whitneyav doesn't converge. Yet I can't rebiuld this error. Anyone an idea what this error means or how to avoid it? What bc should be set for an infinite long wire?

I usw Elmer under Windows 10 and 7 (Elmer 8.0) with a model created in Salome.

The SIF-file:

Code: Select all

Header
  CHECK KEYWORDS Warn
  Mesh DB "." "."
  Include Path ""
  Results Directory ""
End

Simulation
  Max Output Level = 10
  Coordinate System = Cartesian
  Coordinate Mapping(3) = 1 2 3
  Simulation Type = Steady state
  Steady State Max Iterations = 1
  Output Intervals = 1
  Timestepping Method = BDF
  BDF Order = 1
  Solver Input File = inf.sif
  Post File = inf.ep
Coordinate Scaling = 1e-3
End

Constants
  Gravity(4) = 0 -1 0 9.82
  Stefan Boltzmann = 5.67e-08
  Permittivity of Vacuum = 8.8542e-12
  Boltzmann Constant = 1.3807e-23
  Unit Charge = 1.602e-19
End

Body 1
  Target Bodies(1) = 10
  Name = "Body 1"
  Equation = 1
  Material = 1
  Body Force = 1
End

Body 2
  Target Bodies(1) = 11
  Name = "Body 2"
  Equation = 2
  Material = 2
End

Body 3
  Target Bodies(1) = 12
  Name = "Body 3"
  Equation = 2
  Material = 3
End

Body 4
  Target Bodies(1) = 13
  Name = "Body 4"
  Equation = 2
  Material = 2
End

Solver 2
  Equation = MgDyn
  Variable = AV
  Fix Input Current Density = True
  Procedure = "MagnetoDynamics" "WhitneyAVSolver"
  Exec Solver = Always
  Stabilize = True
  Bubbles = False
  Lumped Mass Matrix = False
  Optimize Bandwidth = True
  Steady State Convergence Tolerance = 1.0e-5
  Nonlinear System Convergence Tolerance = 1.0e-7
  Nonlinear System Max Iterations = 20
  Nonlinear System Newton After Iterations = 3
  Nonlinear System Newton After Tolerance = 1.0e-3
  Nonlinear System Relaxation Factor = 1
  Linear System Solver = Iterative
  Linear System Iterative Method = CG
  Linear System Max Iterations = 5000
  Linear System Convergence Tolerance = 1.0e-10
  BiCGstabl polynomial degree = 2
  Linear System Preconditioning = Diagonal
  Linear System ILUT Tolerance = 1.0e-3
  Linear System Abort Not Converged = False
  Linear System Residual Output = 1
  Linear System Precondition Recompute = 1
End

Solver 3
  Equation = MgDynPost
  Calculate Magnetic Field Strength = True
  Potential Variable = AV
  Procedure = "MagnetoDynamics" "MagnetoDynamicsCalcFields"
  Calculate Electric Field = True
  Exec Solver = Always
  Stabilize = True
  Bubbles = False
  Lumped Mass Matrix = False
  Optimize Bandwidth = True
  Steady State Convergence Tolerance = 1.0e-5
  Nonlinear System Convergence Tolerance = 1.0e-7
  Nonlinear System Max Iterations = 20
  Nonlinear System Newton After Iterations = 3
  Nonlinear System Newton After Tolerance = 1.0e-3
  Nonlinear System Relaxation Factor = 1
  Linear System Solver = Iterative
  Linear System Iterative Method = CG
  Linear System Max Iterations = 5000
  Linear System Convergence Tolerance = 1.0e-10
  BiCGstabl polynomial degree = 2
  Linear System Preconditioning = Diagonal
  Linear System ILUT Tolerance = 1.0e-3
  Linear System Abort Not Converged = False
  Linear System Residual Output = 1
  Linear System Precondition Recompute = 1
End

Solver 1
  Equation = Static Current Conduction
  Calculate Volume Current = True
  Variable = Potential
  Procedure = "StatCurrentSolve" "StatCurrentSolver"
  Exec Solver = Before Simulation
  Stabilize = True
  Bubbles = False
  Lumped Mass Matrix = False
  Optimize Bandwidth = True
  Steady State Convergence Tolerance = 1.0e-5
  Nonlinear System Convergence Tolerance = 1.0e-7
  Nonlinear System Max Iterations = 20
  Nonlinear System Newton After Iterations = 3
  Nonlinear System Newton After Tolerance = 1.0e-3
  Nonlinear System Relaxation Factor = 1
  Linear System Solver = Iterative
  Linear System Iterative Method = CG
  Linear System Max Iterations = 5000
  Linear System Convergence Tolerance = 1.0e-10
  BiCGstabl polynomial degree = 2
  Linear System Preconditioning = Diagonal
  Linear System ILUT Tolerance = 1.0e-3
  Linear System Abort Not Converged = False
  Linear System Residual Output = 1
  Linear System Precondition Recompute = 1
End

Solver 4
  Equation = Result Output
  Procedure = "ResultOutputSolve" "ResultOutputSolver"
  Output Format = Vtu
  Output File Name = inf
  Exec Solver = After Timestep
End

Equation 1
  Name = "Wire"
  Active Solvers(4) = 2 3 1 4
End

Equation 2
  Name = "Air+Core"
  Active Solvers(3) = 2 3 4
End

Material 1
  Name = "Copper"
  Electric Conductivity = 59.59e6
  Porosity Model = Always saturated
  Density = 8960.0
  Relative Permeability = 1
End

Material 2
  Name = "Air"
  Electric Conductivity = 0
  Porosity Model = Always saturated
  Density = 1.205
  Relative Permeability = 1
End

Material 3
  Name = "Steel"
  Electric Conductivity = 1.449e6
  Porosity Model = Always saturated
  Density = 8960.0
  Relative Permeability = 1000
End

Body Force 1
  Name = "BodyForce 1"
  Current Density 1 = Equals Volume Current 1
  Current Density 3 = Equals Volume Current 3
  Current Density 2 = Equals Volume Current 2
End

Boundary Condition 1
  Target Boundaries(1) = 5 
  Name = "Ground"
  Potential = 0
  Magnetic Flux Density 3 = Real 0
End

Boundary Condition 2
  Target Boundaries(1) = 6 
  Name = "Potential"
  Current Density = 1e7
  Magnetic Flux Density 3 = Real 0
End

Boundary Condition 3
  Target Boundaries(1) = 4 
  Name = "Border"
  AV {e} = 0
End

Boundary Condition 4
  Target Boundaries(6) = 1 2 3 7 8 9 
  Name = "inf"
  Magnetic Flux Density 3 = Real 0
End
Bavragor
Posts: 32
Joined: 07 Nov 2013, 14:10
Antispam: Yes

Re: BC for infinite longe wire

Post by Bavragor »

I got it on my own. In fact pretty easy. Only have to set AV {e} 2 = 0 and AV {e} 1 = 0 for all BCs in z-direction
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