Electromagnetism: Magnetic Field, change in permeability

AI Thread Summary
The discussion revolves around the effects of material permeability on the magnetic field generated by a Helmholtz coil. The user is investigating how the presence of a cylindrical chamber and a square strut, both with specific permeability and dimensions, influences the magnetic field within the coils. They have successfully applied the Biot-Savart law for the coil's center without the chamber but are uncertain about the changes introduced by the materials. The user seeks recommendations for relevant sections in textbooks like Jackson or Griffiths and is looking for numerical simulation tools to analyze the problem further. They also mention having a CAD model and express interest in finding a free solver for the Laplace equation in 2D.
Helmholtzerton
Messages
30
Reaction score
4
Hello everyone.

I've built a Helmholtz coil and I'm attempting to understand how the magnetic field direction and magnitude will be effected do to a material with a particular permeability.

In the first picture I have an infinitely long cylinder with a particular thickness and permeability. There is a coil around the chamber. My Helmholtz coils are some distance from the chamber. I'm trying to find out how the B or H field is effected by the chamber due to its permeability and thickness. There are three areas that I'm concerned about. I was able to solve this for the center of the coil without the chamber using Biot Savart. I'm not sure what happens when a material is added in between.

In the second picture I have an infinitely long piece of square strut. The is a coil around the strut. The strut is off center to the coil. The strut has a particular height and width. I'm trying to find out how the be field is effected within the coils due to the piece of strut.

Is there a particular section in Jackson or Griffiths that would help me understand this problem? I'm assuming dB/dt = 0 as my coils have been turned on and running for some time.

Thanks to anyone who could provide some insight to this problem.
 

Attachments

  • Cyclinder.png
    Cyclinder.png
    5 KB · Views: 488
  • Square.png
    Square.png
    3.5 KB · Views: 481
Physics news on Phys.org
The cylinders in the sketch have infinite length, the coils do not (just two with zero length each)? I'm quite sure that needs a numeric simulation.
 
Assume just one coil in a plane. I'm pretty sure this will require a numeric simulation as well.

I found an example in Jackson that gives some insight to this problem. I have a CAD model of this. Is there is a free solver somewhere for a problem like this?
 
Have you access to any code solving the Laplace equation in 2D?
You should as a student. I can give you links if you need.
 
Thread 'Motional EMF in Faraday disc, co-rotating magnet axial mean flux'
So here is the motional EMF formula. Now I understand the standard Faraday paradox that an axis symmetric field source (like a speaker motor ring magnet) has a magnetic field that is frame invariant under rotation around axis of symmetry. The field is static whether you rotate the magnet or not. So far so good. What puzzles me is this , there is a term average magnetic flux or "azimuthal mean" , this term describes the average magnetic field through the area swept by the rotating Faraday...

Similar threads

Replies
43
Views
6K
Replies
25
Views
4K
Replies
7
Views
2K
Replies
3
Views
1K
Replies
2
Views
3K
Replies
42
Views
2K
Back
Top