"Larry" wrote in message
...
krj wrote in news:XX_jf.41614$Y82.8182
@bignews4.bellsouth.net:


Nice post, I like your point about using imagination. So, sorry
about this nit pick:

But, alas, how about doubling the number of blades that are
shorter but
produce the same HP?

Sadly, the aerodynamics don't quite work that way. The maximum HP
you can get out of a windmill at a given air speed depends on the
swept area. The actual HP you get out of the area depends on the
efficiency with which you sweep it. With current best blade design
the greatest efficiency comes from three bladed props. If you
reduce the swept area it's most unlikely you can restore the HP
with more blades.

JimB