Wake Turbulence Test

[miikkuke22]

ok but how about one rope on the winglet? how would it perform on the tip?

[eyeammi]

That's not turbulence. They're vortices caused by pressure differentials (lift generation). The high pressure flows around the tip to the low pressure side & rotates into a vortex. (same thing with the aileron). That's why adding the outboard tips stops it. It prevents flow from the underside of the wing from wrapping to the top side at the wing tip. If the winglets are made out of a symmetric airfoil profile, they will not produce a pressure differential & thus not create their own vortices.

[Beamernator]

@eyeammi They will also create thrust.

[GertjanvandenBosch]

@eyeammi Adding wingtips, wingplates or even wingtakns does not stop the vortices, the're are always there when an aerofoil produces lift. Yes, they will reduce some amount of vortices, but not all of it. By reducing the vortices, you reduce your induces drag, only adding wingtips increases parasite drag. And there is always a pressure differential due to the pressure differential of the aerosol where you add the wingtips to.

[jesuistahmid]

can you do the same for raked wing tips ;)

also i have never seen the 3rd design you used on aircrafts... the closest are the airbus a300/10/20 and its much smaller.

[straighttailpilot]

Yeah but what about the tip of the wingtip? how much vortex does it create or does it dissipate it? what is the calculation to know the dimension of the splate?

[Helicopterpilot16]

I do have one question, How did you construct your wing models?

[DrPashupathy]

Nice experiment

[FrekeOne]

Winglets works!

[kartha789]

Great....

[stormthorgerson]

how are we testing w turbulence?

[yournameiswrong]

I would make the string longer

[busabuoy]

Please help me to understand. A vortex is formed at the end of a wing tip due to the pressure differences above and below the wing and this is reduced by adding a Winglet or Wingtip fence. If this is case then in your video you not only reducing the effect but also moving the vortex to then end of the Wing(let). A third (or forth for the Airbus type) piece of string on the outer edges would show this.

[ricardolemke88]

Your analysis is correct. As I remember we had another piece of strip at the end of the winglet before the video, but I don't know why not IN the video :-/ .

But the vortex at the end of a winglet is definitely less strong than at a normal wing tip.

[busabuoy]

Thanks for your reply. I have no access to a wind tunnel but I'd be interested to find out if the two vortices caused by the Airbus type rotate in different directions. Looking from the rear would the upper left one cause a clockwise motion while the lower one a anti-clockwise motion?

[4wheeldrifting]

theoretically there should be no pressure difference on either side of the vertical winglet and hence no vortex. Of course in reality there are pressure differences only they are much smaller and therefore do not create as severe of a vortex and therefore no as much drag. that is the aim anyway

[busabuoy]

The string is moving to quick to see if it's rotating or moving up and down. Can I assume it's rotating?

I remember seeing pods on EA-6B Prowlers with a 'wind mill' power generator on them. In theory if you place them at the back of a winglets, rotating contary to the 'vortex' would that reduce any pressure difference while creating 'free' power?

Try it you know you want to and when it works, don't forget me.

[Helicopterpilot16]

The Angle of attack is differend with winglets compared the wings AOA.

And as said below, there should be no presure difference.

[orgaized4battle]

great demonstration! I've been trying to explain that with all kinds of drawings and bad hand gestures for too long!

[ChrisCooper312]

Very nice and simple way of demonstrating a very important part of aviation. Had to laugh at the aileron control though, not fly by wire but fly by stick :)

[giovii2]

what are wake turbulences??

[ricardolemke88]

i'm german so sorry for faults

there is low pressure above and high pressure below the wing, so the air tries to ballance the pressure and streams from below to above at the end of the wing. this ends in a rotating movement and continues behind the flying wing

i hope i could help :-)

[giovii2]

you did help!...thanks!

[HanGookBoi]

so in other words, its a mini tornado forming on the wingtip.

[foragana]

would you tell please when is this happening???... continuosly all the time???

[777LRtraveler]

No, not continuosly!

It happens, from the moment when the nosewheel lifts off at the take off, through the whole flight, till the nosewheel touches down at landing.

[175Air]

@777LRtraveler That is untrue! It happens before the nose gear lifts off and after it touches down! Around 60-80kts or something like that.

[arias1772]

basically whenever the aircraft is producing lift.

[Helicopterpilot16]

@ricardolemke88 Thats is the same answer I would give, Auf Wiedersehn!

[patrickcramer]

very nice...simple and very useful...congratilantions and thank you for sharing...