extensive golf ball dimple aircraft testing?

StevieTimes

StevieTimes

Line Up and Wait
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StevieTimes
So I did a search, and saw this:
https://www.autoblog.com/2009/10/22/mythbusters-golf-ball-like-dimpling-mpg/

I saw they used pretty huge dimples. It might be interesting to use varying sizes of dimples and check the effects. Once the awesomest sized dimples have been found, I could see future cars coming out "dimpled" from the factory.

After determining the best sized dimples for cars, it would be interesting to try on airplanes as well.

Has any aircraft manufacturer done extensive surface dimple testing?
 
Could've gotten the same results by placing VGs in critical areas of the vehicle.
 
StevieTimes said:
So I did a search, and saw this:
https://www.autoblog.com/2009/10/22/mythbusters-golf-ball-like-dimpling-mpg/

I saw they used pretty huge dimples. It might be interesting to use varying sizes of dimples and check the effects. Once the awesomest sized dimples have been found, I could see future cars coming out "dimpled" from the factory.

After determining the best sized dimples for cars, it would be interesting to try on airplanes as well.

Has any aircraft manufacturer done extensive surface dimple testing?
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I think so. I remember something like that. Maybe it was an after market thing. Like rough tape put on the wing
 
At least I have another excuse not to have to clean the damn thing.

And let's hope the price on all the hail damage planes didn't just go up haha
 
Why are the dimples so huge? That seems overkill
 
Yeah, bugs just aren't a drag penalty. In some highly loaded airfoils (canards), it can cause them to stall at a much higher speed.

13:40 mark

 
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A golf ball is a practical example of the use of the Magnus effect. The underside of the ball counter-rotating against forward travel creates lift for further travel. There is of course a drag penalty.
 
Sac Arrow said:
A golf ball is a practical example of the use of the Magnus effect. The underside of the ball counter-rotating against forward travel creates lift for further travel. There is of course a drag penalty.
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The reduction in pressure drag behind the golf ball due to dimples is the biggest benefit. That's about the only thing they achieved with this car experiment. VGs like semi truck "Trailer Tails", produce a slight increase in MPG.
 
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Velocity173 said:
Yeah, bugs just aren't a drag penalty. In some highly loaded airfoils (canards), it can cause them to stall at a much higher speed.

13:40 mark

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Dam. I wouldn't have figured the bugs would have made that much difference. What is the speed the canard is supposed to stall at? Isn't it just a few knots before the wing? What are the numbers on this? Published wing stall speed, canard stall speed. Was this a known issue with Velocities? Do you think the angle of incidence might have gotten a tad bit off during construction?
 
luvflyin said:
Dam. I wouldn't have figured the bugs would have made that much difference. What is the speed the canard is supposed to stall at? Isn't it just a few knots before the wing? What are the numbers on this? Published wing stall speed, canard stall speed. Was this a known issue with Velocities? Do you think the angle of incidence might have gotten a tad bit off during construction?
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Oh many factors involved. The canard should stall around 55-60 kts for that particular aircraft. This Varieze most likely uses a GU canard. They're bad in bugs and rain. The newer Roncz canard solved the issue for the most part. Canard incidence has somewhat of an influence as well with those that have a decreased incidence, are more susceptible to the nose down pitch. Weight and forward CG will exacerbate the problem as well.

Velocity aircraft generally don't have any issues that I've heard of. Mine will actually pitch up a couple of degrees while flying through rain.

http://www.ez.org/t/cp35-p2
 
Velocity173 said:
Oh many factors involved. The canard should stall around 55-60 kts for that particular aircraft. This Varieze most likely uses a GU canard. They're bad in bugs and rain. The newer Roncz canard solved the issue for the most part. Canard incidence has somewhat of an influence as well with those that have a decreased incidence, are more susceptible to the nose down pitch. Weight and forward CG will exacerbate the problem as well.

Velocity aircraft generally don't have any issues that I've heard of. Mine will actually pitch up a couple of degrees while flying through rain.
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K. I thought it was a velocity, but it was an eze.
 
Tantalum said:
Cool! I assumed they were functioning as VGs, didn't know there was some magnus effect at play as well
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Not only that, but technically, both Coriolis and Eötvös effect as well!
 
luvflyin said:
Dam. I wouldn't have figured the bugs would have made that much difference. What is the speed the canard is supposed to stall at? Isn't it just a few knots before the wing? What are the numbers on this? Published wing stall speed, canard stall speed. Was this a known issue with Velocities? Do you think the angle of incidence might have gotten a tad bit off during construction?
Click to expand...
The issue with bug and rain (and paint stripes and...) on EZs and Quickies and other stuff is that small disturbances can trip the flow on a laminar airfoil from laminar to turbulent, with a resultant loss of lift.

Nauga,
and a guts check
 
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