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Old May 28, 2012, 08:24 PM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
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The dimple effect makes total sense to me. I have spent a lot of time in float planes while working as a mining exploration surveyor, flying as a passenger, not a pilot. All of the pilots say the same thing about the smoothness of the water surface. If there is no wind, and the lake is glassy smooth, it acts as a suction cup and takes more distance and power to get the plane up to takeoff speed. If there is a breeze that creates some ripples, the drag is greatly reduced and the pilot can feel the difference.

Up to a point the bigger the waves, the better. Thanks for that entertaining video.
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Old May 28, 2012, 09:02 PM
Drifting off the reservation..
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USA, LA, Broussard
Joined Jan 2011
2,296 Posts
I had a glider once which featured turbulator spars on the top of the wing. The turbulence on top of the wing is supposed to generate more lift with less drag.

I carried that theory into my RP, where the bottom of the wing is slick (using black stick on monocote) and the top is foam, dimples and all. You want the air to move undisturbed across the bottom of the wing, but the air flowing over the top is better a little "disturbed". Not sure that I want to go so far as to "snakify" the foam though..
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Old May 28, 2012, 09:13 PM
turn, turn, turn.
Athol, Massachusetts
Joined Oct 2005
10,491 Posts
The Radian Pro will go up in the slightest amount of lift.... no dimples necessary.... and yes I enjoyed the video
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Old May 28, 2012, 09:15 PM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
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What does a turbulator look like? I have a plane that has no airfoil at all (just a flat dinner-plate wing) and it flies well. It also glides very well and I was wondering how it could do that. I asked on the thread how a wing with no airfoil could glide so well and one guy mentioned the "KF airfoil" That is a design that provides some sudden "steps" that interrupt the flow and provide lift. I don't really understand how it works, but man that flat wing sure can glide...
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Old May 29, 2012, 04:01 AM
Proud member of LISF and ESL
LI, New York, USA
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Quote:
Originally Posted by tony w View Post
The areas I heated up look just like bumpy snake scales. I held it about 6 inches above a small pan of gently boiling water. I guess that was too much. Question is- should I get new wings?

Tony
To be expected. Just cosmetic. Go Fly!
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Old May 29, 2012, 05:04 AM
Kool Kats Fly RC!! AMA 30462
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United States, CA, Baywood-Los Osos
Joined Feb 2009
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Quote:
Originally Posted by Jovanx View Post
What does a turbulator look like? I have a plane that has no airfoil at all (just a flat dinner-plate wing) and it flies well. It also glides very well and I was wondering how it could do that. I asked on the thread how a wing with no airfoil could glide so well and one guy mentioned the "KE airfoil" That is a design that provides some sudden "steps" that interrupt the flow and provide lift. I don't really understand how it works, but man that flat wing sure can glide...
On a flat-bottom woodie wing turbulators are 1/8' x 1/8" , (or similar/running long grain), balsa strips between the main spar and the leading edge running parallel along the length of the wing, connected to slots cut into the top of the ribs in front of the main spar, (roughly the highest point of the airfoil). There are usually two running side by side from root to tip on each wing. They are indeed designed to create some turbulence/drag over the top of the wing to increase lift on the bottom of the wing, and slow the wing down, (hence their use on "floater" type polyhedral wings, which most woodies have.). When covered, there are rectangular "boxes" between each rib from spar to leading edge, which are in effect "dimples".
When I complete the wing I'm working on now, (99"ws Craft Air Windrifter), I'll post a pic of the turbulators installed, it will make more sense then. Only bummer is it's a 1970's kit, and the slots for the turbulators are not pre-cut into the top of the ribs, (pre laser-cut kit, slots were too small to be accurately machine cut), so all 30-some spars will have the be notched individually, so it might take me awhile.

Actually, I found a pic of someone else's WD that shows the turbulators in front of the main spar.

Sonny
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Old May 29, 2012, 09:42 AM
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Originally Posted by Radio.Active View Post
Dimples, Shmimples... its all good just fly it. Better gas mileage.

http://dsc.discovery.com/videos/myth...-minimyth.html
That was an amazing little piece of work. 11% better fuel mileage? Wow!
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Old May 29, 2012, 10:12 AM
Dixie Normious
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Joined May 2010
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Are those what's called vortex generators? On the new full scale carbon
Cub. And many other aircraft I've seen them.
Carbon Cub SS Walk Around (5 min 10 sec)
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Old May 29, 2012, 10:44 AM
Flies Like Rock
Monument, Colo.
Joined Jan 2005
364 Posts
If it is just cosmetic, I will fly it. I appreciate all the dimple examples, and have one of my own. I have a drift boat used for fly fishing in rivers out west....no motors, just drift down the river using oars to control direction. My brand, Clackacraft, puts dimples on the bottom of the hull, claiming that the boat actually rows easier with them than without.

Perhaps we should call these dimples "snakeulators".

thanks,

Tony
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Old May 29, 2012, 11:20 AM
Dixie Normious
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Quote:
Originally Posted by tony w View Post
Perhaps we should call these dimples "snakeulators".
Tony

Good one!
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Old May 29, 2012, 11:30 AM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
3,169 Posts
Who is going to be the first to dimple a Radian Pro? It would actually be pretty easy to do on a foamie.
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Old May 29, 2012, 12:19 PM
Seeker of Thermals
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United States, MT, Kalispell
Joined Aug 2004
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Quote:
Originally Posted by Jovanx View Post
Who is going to be the first to dimple a Radian Pro? It would actually be pretty easy to do on a foamie.
A soldering iron would do the trick nicely.

--
Greg
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Old May 29, 2012, 12:26 PM
Proud member of LISF and ESL
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A steel ball on a rod. Heat the ball on the BBQ, then melt it into the foam to make the dimples.

Be sure to space them evenly.

Frankly I would expect it to have adverse impact on teh lift of the wings but it might make the fuselage more slippery. I would try the fuse alone, first. Maybe something the side of a large marble would work. Not sure what sort of pattern you would need to follow.
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Old May 29, 2012, 01:04 PM
Drifting off the reservation..
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USA, LA, Broussard
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I guess you would want to copy the pattern of a golf ball. The dimples are offset in a sort of honeycomb pattern.
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Old May 29, 2012, 01:16 PM
Tossing planes into the snow
Canada, BC, Smithers
Joined Nov 2011
3,169 Posts
Why would they have to follow a pattern? I would just put them randomly, using my eye to keep the spacing more or less even. I was thinking of just pressing instead of burning out a hole. Then you could always undo it with the heat treatment.
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