May 28, 2012, 07:24 PM
Tossing planes into the snow
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.
Last edited by Jovanx; May 28, 2012 at 07:53 PM.
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May 28, 2012, 08:02 PM
Drifting off the reservation..
JumpySticks's Avatar
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..
May 28, 2012, 08:13 PM
turn, turn, turn.
The Radian Pro will go up in the slightest amount of lift.... no dimples necessary.... and yes I enjoyed the video
May 28, 2012, 08:15 PM
Tossing planes into the snow
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...
Last edited by Jovanx; May 29, 2012 at 04:04 AM.
May 29, 2012, 03:01 AM
Proud member of LISF and ESL
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!
May 29, 2012, 04:04 AM
Kool Kats Fly RC!! AMA 30462
sonny1's Avatar
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
May 29, 2012, 08:42 AM
Proud member of LISF and ESL
Quote:
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!
May 29, 2012, 09:12 AM
Dixie Normious
Eastcoast78's Avatar
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)
May 29, 2012, 09:44 AM
Flies Like Rock
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
May 29, 2012, 10:20 AM
Dixie Normious
Eastcoast78's Avatar
Quote:
Originally Posted by tony w View Post
Perhaps we should call these dimples "snakeulators".
Tony

Good one!
May 29, 2012, 10:30 AM
Tossing planes into the snow
Who is going to be the first to dimple a Radian Pro? It would actually be pretty easy to do on a foamie.
May 29, 2012, 11:19 AM
Camber down and screw it up.
gdouglas's Avatar
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
May 29, 2012, 11:26 AM
Proud member of LISF and ESL
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.
May 29, 2012, 12:04 PM
Drifting off the reservation..
JumpySticks's Avatar
I guess you would want to copy the pattern of a golf ball. The dimples are offset in a sort of honeycomb pattern.
May 29, 2012, 12:16 PM
Tossing planes into the snow
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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