I always wanted to know what creates upward lift on an aircraft wing?

Question

And how can the principle of Bernoulli's equation be applied when considering about what creates upward lift on aircraft wing. So can you please explain me.

thanks.

Answer 1

Bernoulli's theory works great when you are trying to explain the way a carburettor works.

The problem with Bernoulli is that it 'overlooks' certain basic facts when it comes to aviation theory. For example the theory goes that a depression on the upper surface of an airfoil when there is an air flow creates lift.

But if you ask any pilot that has questioned this theory, they will ask you 'well how does my plane fly upside down?' and they would have a point; if Bernoulli's theory applied, then the plane would be sucked to the ground if it tried to fly upside down.

Also consider if the Bernoulli effect explains flight in powered aircraft how did the Wright brothers ever get off the ground using flat wings? and how does a paper plane fly with flat wings?

Issac Newton is the key here....

The third law of motion explains that each reaction has an equal and opposite reaction.

As a plane is propelled forwards, the wing being tilted downwards (angle of attack) forces air beneath it and downwards. In reaction to this, the wing is pushed upwards by the airflow, producing lift (a bit like the way a water skier stays on top of the water by virtue of the water passing underneath his ski's)

That's how wings work, effectively they are surfing through the air. This is most notable in rotary winged aircraft (helicopters).

Bernoulli does come in to play, as it helps improve efficiency of wing design, but getting planes to fly relies entirely in the laws of newton.

Answer 2

The key here is the difference on pressure. One of the main conclusions of bernulli´s equation is that a moving stream of fluid will have less pressure than a static one. Using this criteria, the wing is designed in a way that the air who goes through the upper part will have to move through a bigger distance and thus will move faster and will have less pressure than the air who moves through the bottom part. This difference of pressure creates the lift.
But what happens when an aircraft is flying upside down?, well, let me tell you that this is usually achieved in aircraft with symmetric airfoils.
A wing´s airfoil can be symmetric or asymmetric. When the airfoil is asymmetric, the wing produces lift with 0 angle of attack, but a symmetric airfoil needs some positive angle of attack to produce lift. By having a posive angle of attack, a symmetric airfoil behaves like an assymetric airfoil with no angle of attack.

Answer 3

No one is really sure. There are several theories floating around out there. However, they must all work because our planes are not falling from the sky.
Actually, they all agree on what must happen, that the airflow across the top and bottom surfaces of a wing form a higher pressure on the bottom surface and a lesser pressure on the top surface so that the "lift" required to keep the plane in the air is maintained, but they do not agree on the mechanics of how that lift is generated by the airflow.

Answer 4

The simple answer is that the shape of the wing causes the air going over the top of the wing to move faster than the air going past the underside of the wing. Because of this imbalance the pressure is lower above the wing and the higher pressure air below the aircraft literally pushes the plane up into the air. There are many complex actions in this equation, but that is the essence

Answer 5

Forget Bernoulli. Well, halfway forget him because he's only half the story! Check out link below on aircraft misconceptions.

Then, check out the link about how an airplane works.

Then, more articles by an actual light sport aircraft designer.

Finally, some amazing STOL homebuilt airplane videos.

Answer 6

Fast moving air creates a low pressure zone above the wing and slow moving air creates high pressure below the wing creating lift.

If you turn on your shower (and have a plastic curtain) the fast moving air will create a low pressure zone inside your shower and the curtain will be 'sucked' in to establish pressure equilibrium. Its the same principle.