interaction of toroid and solenoid - magnetic flux modelled

[bob.rennips]

I used a magnetic flux modelling software so see what happens when a solenoid is place at right angles to a toroid. I know this doesn't mirror the deducted structure of the TPU but bear with me on this...

What is interesting is that the flux lines in the toroid deviate from inside to outside and then outside to inside. What is more if the solenoid in the center was rotated you would get a spiralling, vortex affect, within the toroid.

In other words, if we create a rotating magnetic field, (as per the TPU) around a toroid, (as per the TPU) we get an interesting vortex effect. Note however for this effect the N -S must be pointing into the TPU from the center of the toroid. (Perhaps the combination of fields within Steven Mark's TPU achieves this to some degree).

What is even more interesting is that the spiralling only occurs with an AIR CORE toroid. With an iron core toroid the flux doesn't deviate even with very large solenoid magnetic fields. The magnetic field strength of the toroid and solenoid are identical in both digrams. The only difference is with or without the iron core.

Is this interesting, and more importantly, is there any relevance to the TPU ?

[Nali2001]

what program did you use?

[mikestocks2006]

Hi bob.rennips,

Can you model the same toroid-air core, with a spinning disc magnet in it's center N-S axis perpendicular to the toroid plane?

There is also some work in this forum on homopolar generators, where there is current/voltage creation without back emf. (there is no staionary magnet-stator and/or flux lines there to cut through as the magnet it self is spinning) It maybe related to your modeling too.
Thanks

[Super]

A freeware tool for modelling something like this is "femm", you can get it here http://developer.berlios.de/projects/femm/ read some documentation before you start 

[Nali2001]

Yeah I know femm, but these pictures looked different, so I was wondering about which program was used in this case.