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Old June 12th 06, 01:06 AM posted to rec.aviation.homebuilt
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Default Why don't wings have dimples?

"Dancing Fingers" wrote in message
ups.com...
Hi all,
I always wanted to build my own airplane but the time and money has
eluded me. So I've decided to design and build my own recumbent trike,
with farings. This brings me to my question, if golf balls have
dimples, to help them sail further, why don't wings -- especially for
STOL aircraft? Would putting dimples in my faring reduce my wind
resistance?
Just curious.
Chris


Dimples work on round things under a relativly narrow range of reynolds
numbers (a function of speed, size and properties of air) by helping keep
the boundry layer attached. Golf balls happen to fit into that range and
have the right shape. Gliders sometimes use "turbulator" tape to trip a
laminar boundry layer and make it turbulant so it will stay attached
longer - but the placement is critical (and only works if you have a very
laminar wing to begin with).

So, if you are having boundry layer seperation problems due to the shape of
your fairing aft of the maximum "thickness", then dimples or other boundry
layer devices may or may not help but most likely they will not.

--
Geoff
The Sea Hawk at Wow Way d0t Com
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