[femm] Re: Femmview plots

[Dcm3c@xxxxxxx]

In a message dated 11/26/99 9:08:23 AM Eastern Standard Time, 
istokesrees@xxxxxxxxxxx writes:

> should preface this in saying that I am _not_ particularly
> knowledable concerning EM fields, so please feel free to correct me!
> 
> After creating an axisymetric model of a single conductor current loop,
> femmview shows the contour lines radiating outwards in the plane of the
> loop, but the flux density |B| (the coloured plot) radiates along the
> axis, rather than the current loop plane.
> 
> What do the contour lines represent?
> 
> Why does it appear that one "field strength" is maximal along r (the
> plane of the current loop) and one is maximal along z (the axis of
> rotation)?
>
> Does this have to do with the summation of the field strengths along
> the axis?

The contour lines represent the paths along which flux flows. The density 
plot (i.e. colors) represent the density of flux throughout the contour. The 
reason that there is a high flux density in the center of the ring is that 
all of the flux must pass through the middle of the ring, leading to highly 
concentrated flux.

> I had this "feeling" that there was a null field line along the axis of
> rotation, but now I am doubting that. Can someone please clarify? Is
> there any flux along the axis of a circular symetric system?

For a single current carrying loop, the field can be quite strong along the 
axis of symmetry. However, along the axis, the flux can have no radial 
component--it all has to flow in the "z" direction.

Dave.
--
http://members.aol.com/dcm3c