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Visuals of a Magnetic Field around a Cylindrical Rod (beginner's question)

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This is quite a simple project I know, and I apologize in advanced for taking away any space that might have been used for a more pressing question.

To be quick, I'm working with a professor and he's set the task of me learning to use ComSol comfortably. I'm doing a few simple problems I know the answer to, to verify and get more accustomed to the program. My first is to model the magnetic fields around a cylindrical rod (3D) while a current is being passed through it. The answer, quite simple, is just concentric circles around the wire, however; it's getting to that end result thats proved difficult.

I'm familiar with geometry creation and material selection, the part that's gotten me is which physics I should be using or adding into the study to get the result I want. I'm not sure whether to use

Magnetic and Electric Fields
Magnetic Field Formulation
or Magnetic Fields
And what constraints or factors to add from that physics

If anybody could shine some light on the issue; maybe offer some advice, that would mean a great deal and would help incredibly.
Apologies again for such a meager question/issue.

2 Replies Last Post 16 juil. 2015, 10:01 UTC−4

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Posted: 1 decade ago 12 juil. 2013, 04:27 UTC−4
Hello O'Ryan,

you can, for example, use the magnetic fields interface and apply a single-turn-coil domain to the entity the current flows through. You can directly specifiy the current 's value. The current-conducting entity should have inlet and outlet boundarys that coincide with the boundarys of the whole geometry (like, a sphere of air with radius r and a cylinder with height 2*r along a diameter of that sphere).

Another possibility is to model the problem using magnetic and electric fields and applying an external current density in the conducting domain.

Best regards
Hello O'Ryan, you can, for example, use the magnetic fields interface and apply a single-turn-coil domain to the entity the current flows through. You can directly specifiy the current 's value. The current-conducting entity should have inlet and outlet boundarys that coincide with the boundarys of the whole geometry (like, a sphere of air with radius r and a cylinder with height 2*r along a diameter of that sphere). Another possibility is to model the problem using magnetic and electric fields and applying an external current density in the conducting domain. Best regards

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Posted: 9 years ago 16 juil. 2015, 10:01 UTC−4
Hi,

I have a similar problem. I have a cylindrical rod with a cylinder of air around it, and I'm trying to compute the magnetic field. I'm using Magnetic and Electric Fields. Does there need to be an infinite element domain around the object? In which domains would you apply the external current density, and do you need lumped ports to apply the current?

Many thanks!
Hi, I have a similar problem. I have a cylindrical rod with a cylinder of air around it, and I'm trying to compute the magnetic field. I'm using Magnetic and Electric Fields. Does there need to be an infinite element domain around the object? In which domains would you apply the external current density, and do you need lumped ports to apply the current? Many thanks!

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