Magnetic flux conduit for flux concentration?

[FvM]

The silence is deafening

Patience! People are taking part in the forum discussion in their free time and have usually other jobs to do.

Thanks for visualizing your suggested eddy current pattern. Unfortunately I'm presently not able to verify or falsify one or the other idea (post #18 versus post #11) with a 3D field simulator. You can of course try to derive feasible field/current geometries with pencil and paper applying EM law. An important point is e.g. that field lines have to be closed. Presuming that field lines can't pass the conduit wall, the flux entering one conduit end has to leave the other end, with a constant flux integral along the way.

Regarding the idea of achieving a kind of "flux concentration" with conduits, I doubt that it's possible.

 

[Precision99]

Patience! People are taking part in the forum discussion in their free time and have usually other jobs to do.

Thanks for visualizing your suggested eddy current pattern. Unfortunately I'm presently not able to verify or falsify one or the other idea (post #18 versus post #11) with a 3D field simulator. You can of course try to derive feasible field/current geometries with pencil and paper applying EM law. An important point is e.g. that field lines have to be closed. Presuming that field lines can't pass the conduit wall, the flux entering one conduit end has to leave the other end, with a constant flux integral along the way.

Regarding the idea of achieving a kind of "flux concentration" with conduits, I doubt that it's possible.

Patience? What's that? Never heard of it!

In some sense we are both right. The eddy currents that you sketched will certainly exist, but I claim they are not relevant to the operation of the conduit. And yes, I have FEA modelled the field created by eddy currents of the type that you sketched, and can confirm that the field thus created does nothing to make the split tube behave as a "conduit".

And yes, I have already FEA modelled the effect of the eddy currents that I sketched and described, for the particular example of a thin coil placed against one end of the conduit, and it all works perfectly. There is no doubt at all in my mind that the eddy currents that I have sketched are correct in their general nature, with the specific distribution of the 2 eddy current loops along the length of the conduit depending on the particular geometric details of the exciting coil and its placement with respect to the conduit.

And, as I mentioned, I can give another (very interesting IMHO) reason/insight into why my solution is correct, but that takes effort and a few sketches, though I'm happy to put the effort in if others are interested.

Re "flux concentration" with a tapered conduit, I have thought in some detail about that as well, but thought others might like to think about it first before giving my thoughts. The idea is cute and fascinating, think you not?