> Hello, I am a member of a Binghamton University senior design team and
> our project is a small wind turbine. Since we are engineering students
> I thought an axial flux unit would be appropriate since we could
> actually build it from scratch with some minor alterations to Hugh
> Piggott and Ed Lenz existing designs.
> The problem I am running into is I am the only electrical student
> teamed up with 4 mechanical students. The faculty advisor is a ME as
> well. At this point they are trying to convince me that the alternator
> absolutely must have a nacell. As I understand it all the designs I
> have seen are fully exposed to the elements. In fact, the stator
> requires the same wind that turns the blades to dissapate heat
> generated by the coils. Has anybody tried this and can share thier
MIGHT i suggest looking at the old NACA write-ups. Cowlings and
nacelles have been found to enhance cooling for radial engines and
reduce drag. Of course if radially aligned heatsinks are used, it might
even be worthwhile...
You are right, however, that it adds weight, cost and complexity and may
give little benefit. Their evaluation is based on aircraft experience
(where drag is a critical factor) instead of ground based power
generation (where drag is much less important.
Ask them if a ducted fan would be a better choice, then watch them look
confused as the tip losses suddenly show up as important.
David G. LeVine
Nashua, NH 03060