On Sep 6, 3:51*am, Bertie the Bunyip wrote:
a wrote in news:e5fb9dcd-6bd8-42e3-9a50-f6370d188424
@x35g2000hsb.googlegroups.com:

On Sep 5, 6:46*pm, Leviterande Leviterande.
wrote:
Now woludnt a shorter prop with a bigger chord(and q-tips) move more air
and thus creating equal thrust as a longer propeller with thinner chord?

when I tried the patented fan it was pretty quiet *however.

How did you try the patented fan?

AS for longer chords? Probably not. Think of the *most efficient wings
for airplanes -- the ones that provide the best lift/drag. They are
long and slender. The same principles hold for props. You can be sure
if wide chords were better they'd be showing up on experimental
aircraft, and they are not.

They do actually, and they can be very efficient indeed.

http://www.youtube.com/watch?v=Nxz1UF67EQI

There's also been the Dyke Delta, and the facetmobile, of course.

Bertie

I don't think you'd find these as 'efficient' as conventionally shaped
aircraft, else we'd be seeing competition gliders shaped this way.
Those airplane shapes would have very light wing loading of course,
but huge wetted areas -- think drag.

.. As for using that concept for prop blade shape, , where efficiency
is defined in the conventional engineering sense as power out divided
by power in, long and thin blades seem to win over short and fat.