Electrostatic: Microstrip

Numerical methods and mathematical models of Elmer
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dreadlox
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Joined: 13 Nov 2019, 13:45
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Electrostatic: Microstrip

Post by dreadlox »

Hello Elmer-Users,
I am new to Elmer and I ran into a problem.
I am trying to carry out an electrostatic simulation on a microstrip configuration, which is typical in PCB applications.
It consists of a substrate layer and a conductor sitting on top. The lower boundary of the substrate layer was set to a
potential of 0 and the conductor boundary was set to a potential of 1.
Meshing was carried out with gmsh.

As you can see from the attached Paraview screenshot there does not seem to be any connection between the conductor and the substrate layer.
I also attached the Elmer project files.

Can anybody help me with my project ?
Attachments
Microstrip.zip
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microstrip.png
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mzenker
Posts: 1999
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Electrostatic: Microstrip

Post by mzenker »

Hi,

I suspect that the meshes for the two bodies are not connected. You can check that by zooming to the interface in gmsh. The problem should be solvable in gmsh - I think you have to give a coherence command before meshing. You might ask on the gmsh mailing list if the problem persists.
Or else you switch to Salomé and do a partition before meshing.

HTH,
Matthias
dreadlox
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Re: Electrostatic: Microstrip

Post by dreadlox »

Thanks for the fast reply.
I will have a look at my mesh in gmsh.
kevinarden
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Re: Electrostatic: Microstrip

Post by kevinarden »

Confirmed coincident nodes at the boundary between the bodies.

ElmerGrid 14 2 mesh.msh -merge 1.E-6

converted the mesh and merged the coincident nodes
result.png
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dreadlox
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Re: Electrostatic: Microstrip

Post by dreadlox »

Coherence did the trick... I managed to modify the mesh in gmsh and after that
I got the result I expected.

This is very interesting:
kevinarden wrote: 13 Nov 2019, 19:02 Confirmed coincident nodes at the boundary between the bodies.

ElmerGrid 14 2 mesh.msh -merge 1.E-6

converted the mesh and merged the coincident nodes

result.png
A very fast and easy method to modify and correct the mesh.
How did you find about the coincident nodes?

The results obtained with this method and the results obtained by modification of the mesh
in gmsh are the same.
kevinarden
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Re: Electrostatic: Microstrip

Post by kevinarden »

I have had the coincident node problem several times before. i use salome now which will merge coincident nodes. But in researching ElmerGrid I also found the flag -merge that will also merge nodes on conversion.
annier
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Re: Electrostatic: Microstrip

Post by annier »

Hi,
Since beginning I have been using Salome software for constructing mesh, and had never been through this problem.
It is nice to know that ElmerGrid has interface to convert externally created mesh into ElmerSolver compatible mesh.

Yours Sincerely,
Anil Kunwar
Anil Kunwar
Faculty of Mechanical Engineering, Silesian University of Technology, Gliwice
dreadlox
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Re: Electrostatic: Microstrip

Post by dreadlox »

kevinarden wrote: 14 Nov 2019, 00:01 I have had the coincident node problem several times before. i use salome now which will merge coincident nodes. But in researching ElmerGrid I also found the flag -merge that will also merge nodes on conversion.
Thanks for the update...I will give Salome a try
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