Aerodynamics Discuss the physics of flight revolving around the aerodynamics and design of aircraft.

do ailerons provide lift?

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Old 01-26-2013, 05:15 AM
  #151
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Default RE: do ailerons provide lift?

In a nuetral position they do! or when down like a flap.But only as a control surface It's not lift.You loose lift when you loose wing working surface area
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Old 01-26-2013, 09:14 AM
  #152
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Default RE: do ailerons provide lift?

Quote:
ORIGINAL: charlie111

In a nuetral position they do! or when down like a flap.But only as a control surface It's not lift.You loose lift when you loose wing working surface area
How about when the aileron is up,



























but your inverted... I just couldn't help myself. LOL

Bob
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Old 01-26-2013, 09:41 AM
  #153
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Default RE: do ailerons provide lift?

This seems a very good discussion, I saw this topic earlier but nothing I can share because I' ve got the same answer as most of us here. Good job for bringing it into aerodynamics, I learn something I can use for my hornet. I'm planning to use it as added lift devices. The last time I used it works but the problem was pitching effect that looks like it won't adding lift at all while drag might cause an impending control issue. Hopefully it will help by removing some of the weight in the nose.
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Old 01-26-2013, 10:45 AM
  #154
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Default RE: do ailerons provide lift?

 You win some and loose some.When turning which is what airlerons are for you would get some lift as a flap would on one side and loose winglift surface area on the other loosing lift on that side!
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Old 01-26-2013, 12:28 PM
  #155
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Default RE: do ailerons provide lift?

The simple error that so many make is thinking that the control surfaces are something separate. They are not. They are part of the airfoil for good or bad. Adding strip ailerons to an existing wing which did not have ailerons before isn't simply adding ailerons. Instead it changes the airfoil to a new one. The new airfoil has to be considered in total.

Deflecting a control surface does not simply move that one part. Instead it alters the overall airfoil to change the camber value and angle of attack. This is why we get adverse yaw or even tip stalls in some designs if the ailerons are used strongly during slow flight. The downward deflected aileron increases both the angle of attack and the camber of the airfoil. If near but not at the stall point the new AoA and camber can make the resulting airfoil shift up to the high lift but also higer drag portion of the lift/drag operating range. The extra drag can overcome the wing and cause it to drag back and lose lift instead of banking the airplane as intended. In the extrem case where flying very near the stall the downard aileron can push the change to where the resulting high camber and positive angle of attack increase exceed the stall angle. Then you get a tip stall and drop off which needs some altitude for recovery.

Flaps of various sorts do the same thing. They alter the area of the flapped portion to massively increase the camber and angle of attack for that portion of the wing. In the case of wide chord inboard flaps and outboard ailerons this typically forces the outer wing panels to fly at a low or even negative angle of attack. Thus you get gobs of lift and drag but keep the ailerons working very positively as the outer wing portions are flying at a low Cl and thus low Cd value well below the stall. This can work out very nicely with heavy scale models as it acts like adding a LOT of washout to the tips on command. Even if the model doesn't require any extra lift the safety from tip stalling with the flaps down is worth the addtion for heavy wing loading models.
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Old 01-29-2013, 11:21 AM
  #156
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Default RE: do ailerons provide lift?

Trim the plane to fly straight and level.
Remove one aileron and fly again.
The difference in trim is due to the lift " contribut
ion" of the aileron
There WILL be a change
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Old 01-29-2013, 05:26 PM
  #157
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Default RE: do ailerons provide lift?

Hey, lazy dumb ass here who can't be bothered to do a simple search or read a book but love to post my ignorance and then argue about what I don't have a clue and act as if I do. Got a question.

If I take all the feathers off a birds right wing, can it still fly?
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Old 01-29-2013, 07:16 PM
  #158
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Default RE: do ailerons provide lift?

If it is a left wing type, it can -
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Old 01-31-2013, 01:35 AM
  #159
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Default RE: do ailerons provide lift?

Hey BFoote,

I'm looking for posters like you for a new thread I'm thinking of starting. I can't decide wether to discuss how lift is produced, down wind turns or airplanes taking of from treadmills. What wold you suggest.

Sorry couldn't help myself.

Dave
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Old 01-31-2013, 05:34 AM
  #160
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Default RE: do ailerons provide lift?

 From looking at all the replys I think you now understand how air effects an airplane.The Airleron on the left side in a right turn does lift the wing! But not from anything other than a deflection of the Airflow.The same applys to the right side.It applys forces downward from deflection.Lift and deflection are totally seperate.Only in a neutral possition does an airleron contribute to lift being part of the wing as a Whole!
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Old 01-31-2013, 09:15 AM
  #161
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Default RE: do ailerons provide lift?

Quote:
ORIGINAL: charlie111

From looking at all the replys I think you now understand how air effects an airplane.The Airleron on the left side in a right turn does lift the wing! But not from anything other than a deflection of the Airflow.The same applys to the right side.It applys forces downward from deflection.Lift and deflection are totally seperate.Only in a neutral possition does an airleron contribute to lift being part of the wing as a Whole!

You should re-read the post 5 posts before yours. It gives a fairly concise description of what happens.

It's good you mention the ailerons on both sides. Lots of people miss that detail. But otherwise, you're saying a number of things that aren't right.

Ailerons change the amount of lift generated by their sections of the wing. They do that when neutral or deflected. They do that by changing the airfoil of their sections. The resulting airfoil created then changes the amount of lift being generated and sometimes the direction of that lift.

There are a number of fairly inexpensive books available that explain aerodynamics for non-engineers.

Every one of them includes the ailerons as part of the wing and considers their contribution to be constant. There isn't a time they stop contributing.
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Old 01-31-2013, 09:28 AM
  #162
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Default RE: do ailerons provide lift?

Quote:
You should re-read the post 5 posts before yours.

More like the previous 6+ pages. Love it when folks post to a long thread, but can't be bothered to read what's already there. 
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Old 02-02-2013, 01:53 PM
  #163
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Default RE: do ailerons provide lift?

Quote:
ORIGINAL: gerryndennis

Hey BFoote,

I'm looking for posters like you for a new thread I'm thinking of starting. I can't decide wether to discuss how lift is produced, down wind turns or airplanes taking of from treadmills. What wold you suggest.

Sorry couldn't help myself.

Dave
Treadmills. Definetly treadmills.

People's lazyiness never astounds me. Its a proven fact.

What does astound me is that when lazy people get jerked up short, called to account for their blatant stupid lazyness, they get mad(affronted) and many other people get all weak kneed compassionate actually standing up for these lazy selfish people. That is what I find astounding.
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Old 02-02-2013, 05:38 PM
  #164
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Default RE: do ailerons provide lift?

OK, we've all had some good fun over the past page of posts. But the original topic seems to have fallen by the wayside. Unless anyone has something worthwhile that is ON TOPIC to ask or post please leave it alone.
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Old 02-03-2013, 09:19 AM
  #165
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Default RE: do ailerons provide lift?

It all becomes easy to understand if one grasps the basics .
Anything which produces lift -also produces drag .
You can't just pluck one aspect of air working on a solid object - and get the whole picture.
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Old 02-06-2013, 10:26 AM
  #166
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Default RE: do ailerons provide lift?

After a month of a variety of rather amusing posts, I wonder IF the OP got his answer....

One thing certain, it is proven yet again that....that which is so obvious to so many, is not obvious to all.......
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Old 02-06-2013, 01:20 PM
  #167
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Default RE: do ailerons provide lift?

just  remember guys, this did start out in the BEGINNERS forum. Not everyone knows as much about aerodynamics as you.  I can read that many here don't know either. Yes I could have picked up a book and read about it.  I was only looking for a YES or NO answer. 

THANKS to everyone for the knowledge. I had a nice time reading everyone's thoughts.
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Old 02-06-2013, 01:39 PM
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Default RE: do ailerons provide lift?


Quote:
ORIGINAL: chadxp1

just remember guys, this did start out in the BEGINNERS forum. Not everyone knows as much about aerodynamics as you. I can read that many here don't know either. Yes I could have picked up a book and read about it. I was only looking for a YES or NO answer.

THANKS to everyone for the knowledge. I had a nice time reading everyone's thoughts.
It did? Interesting!

Well.......in a word.....YES!!
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Old 02-06-2013, 05:18 PM
  #169
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Default RE: do ailerons provide lift?


Quote:
ORIGINAL: eddieC
Sorry, but AOA is required for any wing to poduce lift. Zero AOA is the definition of no lift, no matter what airfoil. I suggest a bit more research for a better understanding of AOA.

Are you speaking of the AOA as measured from the chord line to the relative wind?
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Old 02-06-2013, 05:37 PM
  #170
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Default RE: do ailerons provide lift?

Mr. Matt, 
Yes. 
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Old 02-06-2013, 05:45 PM
  #171
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Default RE: do ailerons provide lift?

OK I thought there are plenty of airfoils that generate positive CL at 0 ( or even negative) AOA?

Is that not the case?
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Old 02-06-2013, 06:32 PM
  #172
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Default RE: do ailerons provide lift?

Could you explain how lift is created at a negative AOA? I'm not an aero engineer, so anythings possible.
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Old 02-06-2013, 06:37 PM
  #173
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Default RE: do ailerons provide lift?

I've always seen the AoA referenced to the airfoil center line.

Eddie, what you're referring to is the zero lift angle of attack. Which for cambered airfoils is often a negative angle since the standard is to use the center line (line between the forward most point of the leading edge to the apex of the trailing edge) as the reference for the physical angle of attack to the oncoming airflow.

We see this in the charts attached for the NACA 4412. Note that at a 0 angle of attack that there's still a lot of lift. Depending on which Rn you are looking at the zero lift angle of attack is anywhere from -1 to -5 degrees
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Old 02-07-2013, 07:32 AM
  #174
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Default RE: do ailerons provide lift?

Those good old charts are gibberish to many-
The AOA is is also a meaningless referrence to many people.
What is a true, zero angle of attack?
It is the angle IN FLIGHT, where the wing is producing no lift - just drag.
Can you draw this imaginary line on all airfoils ?
No-
You can guess at it for lots of shapes and get pretty close but once the shape of a perfectly symmetrical foilis altered, the true zero line shifts
A very common, flat bottom , curved top shape - is often thought of as having the zero line along the bottom .
That is a easy referrence line - but not a zero AOA line.
Why?
if the wing moves along on that line . the pressure change under the wing will be very low and above that line - it will be very high.
It will "lift" -simply because the pressure is unbalanced .
You can twist that shape OR force it to travel at a different angle - and ecventually reduce the difference in pressures -above and below the shape- to zero -that is the true zero AOA.
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Old 02-07-2013, 09:45 AM
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Default RE: do ailerons provide lift?


Quote:
ORIGINAL: rmh


What is a true, zero angle of attack?
It is the angle IN FLIGHT, where the wing is producing no lift - just drag.
If you define AOA with reference to the zero lift line, then BY DEFINITION, 0 degrees AOA will not produce lift (that is what the zero lift line is).

That is why I asked eddieC what he meant. He seemed pretty definitive when he said that airfoils cannot produce lift at 0 AOA. I asked if he was referring to the angle of the chord line with respect to the relative wind, which is the only way I have ever seen the AOA reference defined.

As you can see from BMatthews post, you can still get lift at negative A0A.
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