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Old November 5th 08, 04:37 AM posted to sci.energy,rec.aviation.homebuilt,rec.aviation.military,rec.aviation.marketplace,sci.engr.mech
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Default Dimples On Model Aircraft Could Greatly Extend Range

On Nov 4, 4:29�pm, wrote:
On Nov 4, 4:26�pm, "daestrom"
wrote:

wrote:
In rec.aviation.marketplace Gregory Hall wrote:


I wonder if anybody has thought of putting the appropriate dimples
on the surface of propellers? Seems like reducing drag there would
increase RPM and reduce HP required.


While reducing drag would be a goal, fixed propeller systems are
designed to keep the tip velocity under mach 1.


For constant speed props, the RPM is whatever you set it to, again
under mach 1.


True, but reducing Hp requirements would still be an advantage.


� � � � � There's an outfit that markets a perforated tape for
propeller leading edges. The perfs act like dimples. They claim
performance improvements with their stuff, of course. Seehttp://www.dimpletape.com/

� � � � � � Dan


If the Reynolds number isn't between 50,000 - 120,000, it's a scam.


Bret Cahill