How does the wing structure of an air plane help to keep it in the air?

I know it's due to the difference in air pressure but can I have a more detailed answer? Like what causes the difference in air pressure and how it helps the air plane? Thx :) .How does the wing structure of an air plane help to keep it in the air?The shortest and easiest answer is the difference in path lengths between over the top of the wing and below the wing.
The path over the top curvature is longer than the path the air must follow to pass under the wing. So as the air has to travel further over the top, it becomes 'stretched", thus lowering the pressure on the top surface, relative to the bottom surface.
The air flowing under the wing is also somewhat compressed, adding to the pressure difference.
The differences in pressures is the lift pressure available.
With an aircraft, there are 2 force "couples" in play, when the aircraft is in steady level flight.
1) The lift is equal to the weight of the aircraft;
2) The engine thrust is equal to the air drag on the structure.

Technically, a wing section can be considered a cross- section of a venturi tube, and as the Bernoulli family of physicists investigated and proved, if you speed up the flow of a liquid (air, in this case), its pressure must be lower than when flowing slower.

EDIT: Bernoulli MUST be considered! Aircraft don't have flat plate wings, which is what Gintable would suggest, and for VERY sound reasons.How does the wing structure of an air plane help to keep it in the air?CAUTION: be skeptical of any explanation using the name "Bernoulli". That explanation is a popular myth that is based upon faulty assumptions of equal transit time...and much other physics neglected.


The differences in pressure are caused by two phenomena.


One phenomena occurs below the wing...the other occurs above the wing.


Below the wing, oncoming air strikes the (slightly downward tilted) wing, and the wing deflects this air downward. The equal and opposite reaction to the action of deflecting this air downward is the wing receiving an upward lift force from the stagnation pressure.


Above the wing, air flows past the region just behind the wing, not directly entering it. It also entrains existing air with it out from just on top of/behind the wing. This creates a "dead air pocket", a region of low pressure (less amount of air per unit volume than there is in the free stream).


Low pressure doesn't do anything. You only think it applies a suction force...but it really doesn't. All it really does, is relieve the force that air ordinarily applies when at background pressure.


So...on the top of the wing, there is a relief of pressure, and on the bottom of the wing, there is excess pressure.

The NET result is, if you examine it distant from the wing, is that the wing DEFLECTS AIR DOWNWARD. The flow of air downward caused by the wing is called downwash.

This wouldn't happen if the wing were perfectly horizontal. There always needs to be an angle of attack of the chord line of the wing if you wish to get any lift at all.

BUT...a perfectly horizontal surface hit with a parallel wind...is that really a no-lift scenario?
Well...temporarily it is. But it is an unstable equilibrium. ANY slight disturbance will cause an angle of attack of the surface on the wind, and the feedback to that angle of attack is greater lift causing greater angle of attack.

Airplanes have their mass strategically arranged such that the angle of attack remains stable. Should greater than desired angle of attack occur, the weight of the engines and payload will torque the plane back to where it should be. Should too little angle of attack develop, the adjustible wing tips have control systems in them that will re-orient them to restore it back to the equilibrium attack angle.


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Debunking what Technobuff suggests:

"So as the air has to travel further over the top"

WHY? You haven't answered exactly why.
Why is it that you can't just have the air take more time to pass over the top of the wing?
What FORCE is causing the alleged "equal transit time"?


"Aircraft don't have flat plate wings"

Oh...some certainly do...and they indeed work:
http://en.wikipedia.org/wiki/Wright_Flye鈥?/a>
http://en.wikipedia.org/wiki/Lyman_Gilmo鈥?/a>
http://en.wikipedia.org/wiki/Hang_glidin鈥?/a>


It just is a primitive design to make the wings flat. You OF COURSE can do better by modifying the shape of the equipment.

Flat plate wings DO work. Most of the time, they work without us even "asking" them to do so. Ever try riding a bicycle and holding onto a sheet of wood? Kind of a stupid idea to try...and I am sure you can intuitively understand why.


I'm not suggesting that you just ignore anything Bernoulli developed. I am just suggesting that the CAUSE of the need for the popular "Bernoulli explanation" is oversimplified...or just perhaps wrong.