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Magnetic field created by a DC wire

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Hello,

I am a former user of 3.5 version. Now I have switched to 5.5 and I am trying to evaluate the magnetic field created by a DC current though a wire (in 3D), and I have problems.

I have draw the wire as a solid cilinder and the infinite lay as a sphere containing it, selected the materials (copper and air) and the external current option in the magnetic analysis (assigning a J0 to the wire), but it does not work.

The error shows: no solution found. Singular matrix. Empty ecuations. Solution not converging.

May I get any help please?

Thanks in advance

Gabriel


2 Replies Last Post 05.04.2021, 15:15 GMT-4
Robert Koslover Certified Consultant

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Posted: 4 years ago 03.04.2021, 21:09 GMT-4
Updated: 4 years ago 04.04.2021, 11:53 GMT-4

You are not the first person to experience that problem. First, there are a number of application modes, and it makes a difference which one you choose. Second, in general you will need to set the conductivity of your empty-space (air around the wire) to be non-zero. (It can be small, but it can't be zero or the solution can't proceed.) If those hints don't help you enough to find a configuration that works, then I suggest that you post your model to the forum and someone here will likely take a closer look at it and give you more specific advice.

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Scientific Applications & Research Associates (SARA) Inc.
www.comsol.com/partners-consultants/certified-consultants/sara
You are not the first person to experience that problem. First, there are a number of application modes, and it makes a difference which one you choose. Second, in general you will need to set the conductivity of your empty-space (air around the wire) to be non-zero. (It can be small, but it can't be zero or the solution can't proceed.) If those hints don't help you enough to find a configuration that works, then I suggest that you post your model to the forum and someone here will likely take a closer look at it and give you more specific advice.

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Posted: 4 years ago 05.04.2021, 15:15 GMT-4

It works!! Thanks a lot Robert!!

Kind regards

Gabriel

It works!! Thanks a lot Robert!! Kind regards Gabriel

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