Elmer8 gives zero results for electric field

Clearly defined bug reports and their fixes
mzenker
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Re: Elmer8 gives zero results for electric field

Post by mzenker » 16 Aug 2017, 01:15

Hi,

I don't understand why the field gets non-symmetric for potential 4000/0 as opposed to 2000/-2000.
I have had a look at your geometry. Your capacitor plates are in fact just frames filled with air. Did you use the same geometry in ANSYS?
I would make the plates bodies and assign them a material. And I don't think you need the inifinity BC. To determine the electric field, you can use either of the methods given in the previous posts.

HTH,

Matthias

axjjienn
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Re: Elmer8 gives zero results for electric field

Post by axjjienn » 16 Aug 2017, 20:24

Hi Matthais,

It is an open-air capacitor. I am doing explorations for electrostatic precipitators and air filtration, but I wanted to simulate a test case I can benchmark against (a simple open-air copper plate capacitor of reasonable size and easily measurable capacitance).

So I should use a coupled Electrostatic-Static Current solution to solve my problem? I left a void for the conductors because this is the approach taken in the tutorials (both GUI and non-GUI), for the Electrostatic solutions.

If you think this is the wrong approach, I would appreciate any direction you can provide.

regards,

Alejandro

raback
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Re: Elmer8 gives zero results for electric field

Post by raback » 16 Aug 2017, 23:31

Hi Alejandro

The capacitance computation requires two different combinations to determine all the components of the capacitance matrix. The "Capacitance Body" is used to perform the permutations such that potentials are alternatingly 0 or 1. It overruns the standard Dirichlet condition. Also what you see in picture is only the last combination.

-Peter

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