Wide vs narrow blades
On Jul 21, 11:52*pm, harry wrote:
On Jul 21, 11:00*pm, dpb wrote:
On 7/21/2011 1:29 PM, wrote:
...
If you look at the old stereotypical "prairie" style windmills, that's
how they are. A disk with pie-shaped blades angled at 45 degrees,
facing directly into the wind with the help of a fin.
...
None I've seen were actually flat, though. *All ours had a curve built
into the blades; steeper front attack angle than rear. *Dated from
roughly 1910 on thru the 20's...
The old Delco Windcharger (mid-1910s when ours installed; not sure when
they were actually introduced) did have a three-bladed hub; not quite so
aerodynamic as current but certainly reminiscent.
--
The multi-bladed windmills were designed to develope a high torque at
low speed, most were for pumping water. *Avoided the need for a
gearbox.
Electricity production is an entirely different matter.- Hide quoted text -
- Show quoted text -
You _are_ aware that wind turbines, at least those honkin big ones,
are slow speed?
Harry K
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