Simulation of electric field inside tube with cutout

Numerical methods and mathematical models of Elmer
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alex.neal
Posts: 3
Joined: 24 Mar 2017, 14:31
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Simulation of electric field inside tube with cutout

Post by alex.neal » 14 Sep 2017, 13:57

Hello everyone,

I start the user Elmer and I need a help.

How correctly to set a similar configuration for calculating the electric field inside the tube (black-dielectric):
geo.jpg
(25.07 KiB) Not downloaded yet
The black side - dielectric, orange side - anode&cathode.

I need to calculation electric field inside a tube but with some specificity. So, from 0 to Alpha_1 we calculation with potential Phi1 and Phi2 on r1 distance , but from Alpha_1 to Alpha_2 we calculation with potential Phi1 and Phi3 on r2 distance. How do I set this range in Elmer ? I created geometry in GMesh, namely one cylinder placed in another.

I'll be very grateful for the help!

Regards,
Alex.
Last edited by alex.neal on 18 Sep 2017, 17:27, edited 3 times in total.

mzenker
Posts: 1747
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Simulation of electric field inside tube with cutout

Post by mzenker » 14 Sep 2017, 14:14

Hi,

I cannot open your google drive files, my company's IT blocks them. You can upload the files directly if they are less than 1 MB.
So without knowing the exact geometry, I would propose you open the mesh with ElmerGUI, use the Electrostatic or Static Current solver (depending on the materials: if you have only isolators, it's Electrostatics), set the potential as boundary condition, and that should be it. Then you get the potential as result. To get the field, you can either use the FluxSolver or do it in the postprocessing stage, see this thread: viewtopic.php?f=3&t=4356.

For more information, you can search this forum and consult the documentation: ElmerGUI manual, Solver manual, Models manual, Tutorials.

HTH,
Matthias

alex.neal
Posts: 3
Joined: 24 Mar 2017, 14:31
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Re: Simulation of electric field inside tube with cutout

Post by alex.neal » 14 Sep 2017, 15:15

mzenker wrote:Hi,

I cannot open your google drive files, my company's IT blocks them. You can upload the files directly if they are less than 1 MB.
So without knowing the exact geometry, I would propose you open the mesh with ElmerGUI, use the Electrostatic or Static Current solver (depending on the materials: if you have only isolators, it's Electrostatics), set the potential as boundary condition, and that should be it. Then you get the potential as result. To get the field, you can either use the FluxSolver or do it in the postprocessing stage, see this thread: viewtopic.php?f=3&t=4356.

For more information, you can search this forum and consult the documentation: ElmerGUI manual, Solver manual, Models manual, Tutorials.

HTH,
Matthias
Sorry,

I attached a geometry and thanks for the answer.

Regards,
Alex.

annier
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Re: Simulation of electric field inside tube with cutout

Post by annier » 18 Sep 2017, 12:08

Alex,
1. You need to draw spherical geometries (multibodies) in accordance to your physics.

2. Please see tutorials on capacitances of Elmer (GUI and nonGUI) so that you can basically utilize the PDE of Electrostatics to simulate your geometrical conditions.


Yours Sincerely,
Anil Kunwar

alex.neal
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Joined: 24 Mar 2017, 14:31
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Re: Simulation of electric field inside tube with cutout

Post by alex.neal » 18 Sep 2017, 17:24

annier wrote:Alex,
1. You need to draw spherical geometries (multibodies) in accordance to your physics.

2. Please see tutorials on capacitances of Elmer (GUI and nonGUI) so that you can basically utilize the PDE of Electrostatics to simulate your geometrical conditions.


Yours Sincerely,
Anil Kunwar

Hi, Anil

For first step
I created this geometry:
tube.geo
(257 Bytes) Downloaded 30 times
&
first step.jpg
first step.jpg (146.66 KiB) Viewed 554 times
And following the example Electrostatic equation – Capacitance of two ball (p.23) : http://www.nic.funet.fi/index/elmer/doc ... orials.pdf Set the same conditions, except the value for the potentials

Code: Select all

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

Simulation
  Max Output Level = 5
  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 = case.sif
  Post File = case.vtu
End

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

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

Solver 1
  Equation = Electrostatics
  Variable = Potential
  Procedure = "StatElecSolve" "StatElecSolver"
  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 = BiCGStab
  Linear System Max Iterations = 500
  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

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

Material 1
  Name = "Material 1"
  Porosity Model = Always saturated
  Relative Permittivity = 1.0
End

Boundary Condition 1
  Target Boundaries(1) = 1 
  Name = "finite"
  Electric Infinity BC = True
End

Boundary Condition 2
  Target Boundaries(1) = 3 
  Name = "bc1"
  Potential = 1000
End

Boundary Condition 3
  Target Boundaries(1) = 2 
  Name = "bc2"
  Potential = 0
End
But i can't give the electric field map inside tube with ParaView, because ElmerSolve issues a zero.
Could you help me set the boundary conditions for Elmer ?

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