[SOLVED] MagnetoDynamics WhitneyAV: zero electric field

Numerical methods and mathematical models of Elmer
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ivanov
Posts: 11
Joined: 25 Aug 2014, 12:51
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[SOLVED] MagnetoDynamics WhitneyAV: zero electric field

Post by ivanov »

I am trying to get a simple solution for electromagnetic field generated by conductor with an alternating current. For some reason in case of transient solver it results in zero electric field and zero current in conductor, although magnetic field seems to be ok. The current is supposed to be set by alternating potential difference at the conductor ends.

I have tried to uncomment "Calculate Current Density = Logical True; Calculate Electric Field = Logical True" in test mgdyn_transient, no success either.

What am I doing wrong?

Elmer Vesrion 8.2 Rev: 214e99e, result files are in vtu format, postprocessor being used is ParaView 5.0.0. Link to project archive https://www.dropbox.com/s/upi230hu75r8d ... t.zip?dl=0

Code: Select all

Header
  CHECK KEYWORDS Warn
  Mesh DB "." "mesh"
End

Simulation
  Coordinate System = Cartesian
  Coordinate Mapping(3) = 1 2 3

  Simulation Type = Transient
  Timestepping Method = BDF
  Timestep Sizes = $ 1/10
  Timestep Intervals = 10

  Steady State Max Iterations = 1
  Post File = "result.vtu"
End

Constants
  Permeability of Vacuum  = 1.257e-6
  Permittivity of Vacuum =  8.85418782-12
End

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

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

Solver 1
   Equation = "MGDynamics"

   Variable = String "P"

   Procedure = "MagnetoDynamics" "WhitneyAVSolver"Elm
   Linear System Symmetric = Logical True
   Linear System Solver = "Iterative"
   Linear System Preconditioning = None
   Linear System Convergence Tolerance = 1e-12
   Linear System Residual Output = 1
   Linear System Max Iterations = 5000
   Linear System Iterative Method = BiCGStabl
End


Solver 2
  Equation = "MGDynamicsCalc"

  Procedure = "MagnetoDynamics" "MagnetoDynamicsCalcFields"
  Linear System Symmetric = True

  Potential Variable = String "P"

  Calculate Current Density = Logical True
  Calculate Electric Field = Logical True
  Calculate Magnetic Field Strength = Logical True
  Calculate Joule Heating = Logical True

  Steady State Convergence Tolerance = 1
  Linear System Solver = "Iterative"
  Linear System Preconditioning = None
  Linear System Residual Output = 0
  Linear System Max Iterations = 5000
  Linear System Iterative Method = CG
  Linear System Convergence Tolerance = 1.0e-4
End


Equation 1
  Name = "System"
  Active Solvers(2) = 1 2
End

Material 1
  Name = "Air"
  Relative Permeability = real 1
  Relative Permittivity = real 1
  Electric Conductivity = real 0.0
End

Material 2
  Name = "Copper"
  Relative Permeability = real 1
  Relative Permittivity = real 1
  Electric Conductivity = real 58e6
End

Boundary Condition 1
   Target Boundaries(3) = 1 2 4
   P {e} = Real 0
End

Boundary Condition 2
   Target Boundaries(1) =   3 
   P {e} = Real 0
   P = Variable Time
     Real MATC "sin(2*pi*tx)"
End

Boundary Condition 3
   Target Boundaries(1) = 5 
   P {e} = Real 0
   P  = Real 0
End
Last edited by ivanov on 07 Aug 2016, 20:09, edited 1 time in total.
kataja
Posts: 74
Joined: 09 May 2014, 16:06
Antispam: Yes

Re: MagnetoDynamics WhitneyAV: zero electric field and current

Post by kataja »

Nothing. There was a bug in MagnetoDynamicsCalcFields (the post processing solver) that caused the electric field to become zero. It's fixed in latest devel version in the github (e69732a).

Thanks!
Juhani
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