Wingtip vorticies: Their benefits?

[AirBadger]

Wingtip vortices are caused by the high pressure air flowing from the bottom wingtips to the top wingtips. This causes induced drag. Induced drag increases as speed decreases, this is why slow heavy aircraft in landing config have larger vorticies which are of course more dangerous. Winglets reduce the induced drag caused by vortices which in turn improves efficiency.

 

[152SIC]

Winglets can also provide a bit of forward lift (ie: thrust.) It is not alot, but every little bit can help.

The wingtip vorticies also are far more pronounced while in slower flight because of the greater lift. This is why you should pitch for airspeed while doing a short field landing at a high angle of attack.

 

[avbug]

Wingtip vortices are useful for dispersing chemical and increasing spanwise distribution of chemical during low level application. Vortices also serve to create turbulence behind the aircraft and enhance chemical penetration into crops or plant canopies.

While under tow behind another aircraft, the preceeding aircraft provide a glider pilot a tactile cue to staying centered behind the tow aircraft. While a bit of a stretch, this may be considered somewhat of a benifit.

While not wingtip related, and while not aircraft related, the vortices behind a semi truck helps keep a bike driver awake on the road, when drafting trucks on the highway.

 

[The_Russian]

Are you thinking of wing vortex generators as opposed to the vorticies themselves?

No, I was thinking of winglets. I read the question wrong.

Nope. absolutely, 100% wrong. Go back and review basic aerodynamics.

Not entirely. I should have clarified my position. For some reason I thought we were speaking directly in reference to winglets. I must have read the first post wrong. And please, learn how to speak to others respectfully when posting. Remember that constructive critisism has a greater benefit when posting on this board. Not just for the persons on here, but for the whole.

Here is a re-attempt at the first post: (Now that I have re-read the question)

Wingtip vortices only increase induced drag within their area of contact with the wing. This is a resultant of the downwash flow of the vortex rotation. The only loss of lift the vortex creates is due to a pressure loss caused by lateral flow towards the wingtip. However, the loss of pressure is far outweighed by the decrease in induced drag caused by the lateral flow. When winglets are installed, the vortex is exacerbated which causes the lateral flow to increase. Winglets also smooth the flow of air into the vortex core. Both of these effects lower the induced drag over the cumulative surface area of the wing. This results in higher TAS and fuel savings. Winglets are also used to move the vortex to the exact location of the wingtip or beyond that. This eliminates the induced drag on the wingtip and once again increase fuel savings and overall TAS. I agree that ground effect lessens the effect of the wingtip vortex. Thus, decreasing induced drag.

Wingtip vortices have great benifits. However, they must be controlled to obtain these benifits.

 

[cathaywannabe]

O.K. smart guys - here is another question.

As an airplane slows and maintains straight and level flight, will induced drag increase or decrease?

 

[152SIC]

Induced drag increases in that case.

"When winglets are installed, the vortex is exacerbated which causes the lateral flow to increase"


Winglets inhibit the vorticies which develop aorund the wingtips; therefore reducing induced drag.

Also wingtip vorticies do not have many positive benifits, besides perhaps in chemical applications.

 

[gsrcrsx68]

O.K. smart guys - here is another question.

As an airplane slows and maintains straight and level flight, will induced drag increase or decrease?

Increases.

 

[AirBadger]

Induced drag decreases with speed, parasite drag increases with speed. Theres a good chart somewhere that shows this.

 

[A Squared]

Not entirely. I should have clarified my position. For some reason I thought we were speaking directly in reference to winglets. I must have read the first post wrong.

Right, you "misunderstood" You thought the question asked about winglets


Sure, that's why you wrote

"Wingtip vorticies help to reduce induced drag by increasing the lateral flow of air over the wing."

Uh-huh, you wrote "wingtip vortices" because you really meant winglets.

Look, it's very clear what you meant, and you clarified exactly what you meant in your second post. Now you are trying to claim you didn't really say that and it's all a big misunderstanding.

 

[SPilot]

http://www.rexresearch.com/klinfogl/klinfogl.htm

What do you guys think? Should I take a chain saw and cut away a better part of the wing? Will it fly? Will insurance cover it?