Re: Van de Graaff generator and absurdities beginning in modern physics

On Feb 11, 8:23 pm, castanaly...@xxxxxxxxx wrote:

Direct calculation of inductance for a coil C.V. Dodd & W.E. Deeds J.
Appl. Phys. vol 39 p 2829 (1968)

I checked my archive of EM papers and don't have it. I looked online
but didn't come up with it, so I'll have to dig a bit deeper the old
fashioned way (library). Thanks much for the reference, though!

I did find the following online: Micolau, IEEE trans. Magnetism,
2004...

Abstract
"We propose a rigorous model of the electromagnetic field in a
conductive circular cylinder illuminated by an arbitrarily shaped and
oriented current-carrying coil placed nearby for nondestructive
evaluation at eddy-current frequencies. The model is based on a dyadic
field formulation, and its modularity enables handy generalizations to
a multilayered cylindrical structure that might be affected by various
defects. We give a variety of numerical results about the primary
electric field within the cylinder in both canonical and practical
cases in order to illustrate pros and cons of the solution method. The
results agree quite well with known analytical results (which are
available only in highly symmetrical cases), and fairly well with
results yielded at high computational cost by an industrial finite-
element code in more general cases."

What I found interesting is that this is a calculation of mutual
inductance which is much easier to do than self-inductance, and still
they indicate that solutions are numerical (in 2004) except for the
few analytical results for "highly symmetrical" cases.

I'm not saying anything yet about Dodd and Deeds because I haven't
seen their paper, but if all problems were solved in 1968 I wonder why
people don't know it in 2004...

But again, thanks for the reference and I do intend to give it a
peer!








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