RE: do ailerons provide lift?
 

Of course ailerons lift if you want em to

RE: do ailerons provide lift?
 

<div>
</div><div>Yes !</div>

RE: do ailerons provide lift?
 

hi guys i am a newbie here trying to figure out how to post a new thread i guess thats what they call it.any help would be greatly appreciated.

RE: do ailerons provide lift?
 

Welcome Chuckaluck.:D

Bob

RE: do ailerons provide lift?
 

Ok, I don't understand this comment (that is not to say its wrong, but please explain). It seems to me, that a wing with a SYMMETRICAL airfoil would produce no lift w/o a postive AOA. But a semi-semmetrical, or a flat-bottom wing does produce lift, even with a zero-degree AOA. All of the afore mentioned airfoils increase lift with a + AOA, but I am not understanding how it would be "required" to have a positive AOA to achieve lift?

~Dave

RE: do ailerons provide lift?
 

I think someone just made a mistake
AOA is sometimes misunderstood
some think the bottom of those flat bottomed things is the Zero line .

RE: do ailerons provide lift?
 

<div>
</div><div>Sorry, but AOA is required for any wing to poduce lift. Zero AOA is the definition of no lift, no matter what airfoil. </div><div>I suggest a bit more research for a better understanding of AOA. </div>

RE: do ailerons provide lift?
 

1. What's the sarcasm about? I stated "IMO" and i stand by it. Everyone is entitled to their opinion and be part of a reasonable discussion.
2. I didn't say that the ailerons don't affect flight characteristics. You need to read the post, then think about your reply before hitting the OK tab.
3. How can an aileron that is parallel produce lift as there is no difference in air pressure top and bottom? The aileron when deflected changes the AOA which puts air pressure against the surface causing the plane to roll.
The only thing that keeps a flat plan foamy in the air is the AOA, which is attained by the propellor thrust and applying elevator, which again is changing the AOA. Cut the throttle and the plane will fall as there is no air pressure against the wing or air pressure differential to hold it there.
4. That's just being silly saying to remove an aileron and fly.
5. But hey, that's MO and you're the guy at the field who is always right.

RE: do ailerons provide lift?
 

Wouldn't a flat bottom wing produce lift with a zero AOA, as the air speed over the wing is faster than the air speed under the wing, thus creating a low pressure area above the wing???
AOA would then be required to alter altitude.

RE: do ailerons provide lift?
 

Thank-you for finally pointing out some basic aerodynamics for our modeling friends.

You guy's surely have hear the old saying "Left Thumb Dumb".
This whole discussion has not highlighted the point that airplanes perform around three axis's
not two. A coordinated turn requires all three inputs. The down aileron does extend the upper camber of the
wing, (thats what makes the wing roll to begin with). The rudder input rotates the nose through direction of the
turn assisting the Aileron. The elevator is used to maintain Alt. as the lift coeffiecent has been reduced.

Lets not forget that all control surfaces work on Bernuli's principle. As speed increases, pressure decreases.
If you think about a molecule of air as a ball, as it hits the leading edge it splits. The half that's traveling around
the upper surface of the wing has to go faster for the two halves to reach the trailing edge at the same time.
Therefore you have less pressure on the upper surface. All control surfaces work as a function of pressure, not
from deflecting the air flow.

RE: do ailerons provide lift?
 

Guys, discussions of the basic aeronautics questions are fun, but often unnecessary. You see, the basic aeronautics questions have answers that have been around since the Wright brothers. They don't need figuring out by anyone.

Want to know if ailerons provide lift? Aeronautical engineers and model designers and pretty much everyone with any understanding use WING AREA in their calculations. The wing area includes all the wing surface and that is figured from the outline of the airplane from above. Some people call it the planform view. Others simply talk about the wing area, assuming anyone that understands aeronautics knows that ailerons are part of the wing etc.

When those guys figure the lift provided by their chosen wing design, they work with the wing area and it includes the ailerons. Lift is what holds the airplane up. The wing is the thing that creates lift. It includes the ailerons.

Flat board wings fly. Symmetrical wings fly. Cambered ones fly. They all have to create lift to fly. Every square inch of their wing area is considered when figuring how much lift they produce. The ailerons are considered as part of the area creating lift.

RE: do ailerons provide lift?
 

OK, so how about ailerons that aren't part of the wing? The Stuka and Ju-53 are airplanes that have isolated ailerons. They are not part of the wing. They do not touch the wing in any attitude and are connected by rather small offsets.

When the designers of those airplanes came up with their somewhat unique layout, they included the area of those remotely attached surfaces with the area of the wing to figure wing loading, pitch stability etc.

Yup, ailerons are considered to provide lift. And it's the lift designers consider when figuring what the plane can carry and whether it can fly with or without carrying anything.

RE: do ailerons provide lift?
 

Beautifully summarized !

Lift is a force.

Static pressure is a force exerted (more or less perpendicularly) over a finite area.

Lift = Area x Pressure (differential between static pressure at bottom and top surfaces of the wing).

Any area having different static pressures above and under itself develops a force toward the area of less pressure.

More AOA of any surface = More pressure differential (Higher coefficient of lift or CL) = More drag (Higher lift costs energy)

More camber of any surface = More pressure differential (Higher coefficient of lift or CL) = More drag (Higher lift costs energy)

Copied from http://en.wikipedia.org/wiki/Junkers_Ju_87

"To ease the difficulty of mass production (of the Junkers Ju 87A), the leading edge of the wing was straightened out and the ailerons' two aerofoil sections had smooth leading and trailing edges."

In that case, the aileron was a little wing with proper airfoil (located away from the airstream leaving the main wing) and the roll was achieved by changing the AOA of those little wings (working in tandem with the main wing).

During the first times of aviation, before ailerons were invented, roll was achieved by warping the whole wing (hence, modifying the AOA of the airfoil progressively along the wingspan).

http://en.wikipedia.org/wiki/Wing_warping

RE: do ailerons provide lift?
 

Ok, I guess was referring more to incidence than AOA relative to the chord of the airfoil profile. But I guess that if I assume a "typical" mounting position for each of the airfoil types, symmetrical, semi-semmetrical, or flat bottom, Two produce lift due to the airfoil shape, and one does not. The airfoild has an inherent AOA based on the shape, where fully symmetrical does not.

RE: do ailerons provide lift?
 

Sorry for the confusion, I went back and read my post and meant to say, unless you are using an asymmetric airfoil then a positive AOA is required to produce lift. I hope this helps.

Bob

RE: do ailerons provide lift?
 

Don't take this too hard, but you really don't need to come up with new meanings for the terms that have been defined for years.

There aren't inherent AOAs. The AOA is simply the angle the wing is encountering the air. Airfoils don't have inherent AOAs.

If you were referring to incidence, consider that it's simply the angle the wing is attached to the airframe.

Both AOA and incident angles are the result of the overall design of the entire airplane and the way it's being used. They change in use. The AOA changes when the plane slows, is more heavily loaded, or less... etc. The AOI of a airfoil is chosen when the designer works out how fast he wants the plane to operate, how much he expects it to carry... etc.

All the terms already have definitions. Use the term when the definition fits and all the argument back and forth trying to figure out what is meant gets chopped down to the issue being discussed.

RE: do ailerons provide lift?
 

Have you ever flown an airplane that shed an aileron or a wing half for that matter? I have, you find out real quick what the absence of wing area does on any part of that wing while flying.;)

Bob

RE: do ailerons provide lift?
 

BTW guys.............

"Basics of R/C Model Aircraft Design" by Andy Lennon is sold in most of the better LHSs. I think Tower sells it too.

It's an excellent way to find out what all the terms mean, and answers questions like this one. It's an excellent book. And sells for less than a gallon of 15%.

RE: do ailerons provide lift?
 

<div>
</div><div>You're assuming there's no difference in air pressure. Can you prove that assumption?</div><div>
</div><div> </div><div>Bernoulli isn't the only principle at work. Remember AOA? Equal and opposite reaction from deflecting the surface, and I believe it has more effect than Bernoulli. Look at a 3D airplane that basically never stalls (as long as the engine is running). It's almost all AOA, going from a prop hang and transitioning to forward flight. </div><div>
</div><div>IMO Mr. Bernoulli gets way too much credit. :)</div>

RE: do ailerons provide lift?
 

I put the word "inherent" in front of AOA to describe my point, not to create a new meaning for anything? Most flat bottom wings are mounted in such a way that the AOA is already included in the way the wing is mounted to the fuse,, which may be zero + incidence.

RE: do ailerons provide lift?
 

All I can say is I used to race Quarter Midgets/When we used real engines/.15 size.You want lift in a hard,bank and yank,left turn add a bit of right rudder.Right turn,add some left rudder,saved me from climbing,down wind,and diving upwind.I might be wrong but it worked for me.Thing about racing is,no one will tell you anything,bet me.

RE: do ailerons provide lift?
 

The problem with this sort of thread is that everyone "is correct" regardless of what the engineers say. Even I was correct in my input. Imagine that.

As long as no-one starts calling someone names and getting personal, hey, knock yer'selves out trying to explain it.

CGr.

RE: do ailerons provide lift?
 

Sorry, but you need to find out what AOI and AOA really are. Placing any wing of any airfoil onto the fuselage establishes the incidence. And they are usually placed according to the angle of attack that airfoil needs to carry the weight at the speed chosen.

Incidence IS the angle the wing is installed and can't be "zero + incidence" because that would be "zero + itself".

RE: do ailerons provide lift?
 

Your saying that a fully symmetrical wing, that theoretically has no lift (zero), plus, lets say, a 2 degree incidence cant produce a postive AOA?

RE: do ailerons provide lift?
 

To further what Da Rock is telling you, you are confusing Angle of Attack and Angle of Incidence. They are two totally different things and should NOT be mixed as you are doing. For example, pretty much all aerobatic planes, such as the Extras, Edges, Yaks, etc, are set up with 0 degrees incidence all the way around, yet they still fly right? That is because angle of attack and angle of incidence are different things, and work differently. If they worked the way you are suggesting, none of these aerobats would get off the ground.

I did up a couple of quick drawings that will hopefully help your understanding. Also, here are a couple of quick points to help seperate the two as well.

<u>Angle of Attack</u>-this is the angle between the chord line of the airfoil and the direction of the relative wind. In simple terms, the angle that the wing meets the air.

-Depends strictly onAIRFLOW direction
-Does not matter how the wing is mounted to the fuselage
-Changes in flight. Pilot can control this, primarily with elevator input (pitching the nose up or down)
-Does not matter which way the aircraft is pointed, again, see point # 1

<u>Angle of Incidence</u>-this is the angle between the chord line of the wing and the longitudinal axis of the fuselage. To simplify, the angle the wing is mounted on the fuselage.

-Is fixed during construction
-The angle of incidence does not change in flight. (Disregarding the effect of flaps or other moveable surfaces)
-Pilot can not change the angle by manipulating the controls, it is fixed.
-Has no effect on angle of attack in flight.

Here are my pictures, hope they help.