2006-11-12 22:53:56 · 17 answers · asked by jeric 1 in Cars & Transportation ➔ Aircraft
The wings of a commercial airplane develop lift by designing a curved surface to the top side, which is more efficient than flat for an aircraft that flies at speeds less than mach 1. This is called camber. Air then flows faster over the top because it has to squeeze between the wing and the air layer above it. This is accomplished by the molecules of air spreading away from each other. When this happens it is said that the air has less pressure or a suction effect. As long as the airplane is moving forward at a fast enough speed, there can be low pressure on top of the wing and lift is created which counteracts the weight of the airplane.
An added benefit of a thick wing is that fuel can be stored in them.
2006-11-13 03:37:11 · answer #1 · answered by mach_92 4 · 1⤊ 0⤋
Do you mean flat in cross section, or flat as in both wings in the same geometric plane?
The first interpretation of the question has been answered already: the cross section determines the velocity of air over the top and bottom surfaces of the wing. It is the difference in the two velocities that creates lift. Air flows faster over the top of the wing than the bottom. Bernoulli's principle states that faster moving air creates less pressure (all other things being equal). The faster air above has lower pressure than the slower air below and voila, lift!
As for the second interpretation, I don't know. Most wings tilt upward from the fuselage (i.e jetliners), but a few such as the F-104 Starfighter, tilt downward.
2006-11-13 13:37:59 · answer #2 · answered by Meresa 3 · 0⤊ 0⤋
There are 2 reasons:
1) the first is aerodynamic: thin and flat airframes are not efficient creating lift, and commercial airplanes are wanted to be as efficient as possible. Flat and thin airframes are used only for mach numbers greater than 1, and when is not required high efficiency at low air speeds. In fact military fighters have quite flat wings, while there are no supersonic commercial airplanes.
2) the second is structural: If the wing is thinner it's structurally less rigid, and has to be reinforced so it will result heavier. If it's thick, it can be lighter.
And if the wing is thick there is more space for fuel.
2006-11-13 10:16:52 · answer #3 · answered by sparviero 6 · 1⤊ 0⤋
no problem,..... first of no plane can have a flat or level wing because that would provide no lift for the aircraft. A average slope of an aircrafts wings is about 30 degrees on a plane with its wing on the bottom or middle. when the wing is on top it is much less than 30degreez. with commercial aircraft the wings are placed about half way up the plane.this is done because of the high altitude ad speed that they fly at. when your flying fast and high like that the the wings being at a lower gives you more control,better lift ratio, and less drag. They slant the wings toward the back of the plane instead of sticking straight out,because when your at high altitude and speed the air is light. by slanting the wings back it gives the wing more area,... that it will need the keep it lifted and flying when your in that thin air. slanting them also reduces the amount of drag the wings create....thats something u dont want when your trying to fly fast and high. hope that helped yah
2006-11-13 11:00:13 · answer #4 · answered by anthony conant 2 · 0⤊ 1⤋
They are curved for streamlining and strength.
A thick wing is much stronger than a thin wing (think construction paper compared to corrogated cardboard) and gives room to store fuel.
A box shaped cross section would not be areodynamically efficient, so the leading edge is curved to reduce the pressure in front of the wing and tapered to a point in the rear to increase the pressure behind it, reducing (not eliminating) drag.
As for all this curved on the top to produce lift BS, how do airplanes fly upsidedown? Any flat plate will produce lift, camber just helps airflow remain attached at high angles of attack. Also the supercritical airfoils used on all modern airliners are curved on the bottom and relatively flat on top.
2006-11-13 12:52:32 · answer #5 · answered by Anonymous · 1⤊ 0⤋
The wings are curved to provide a pressure gradient around the wing. The pressure gradient allows lift. If there is no camber angle on the wing there is no pressure gradient, therefore no lift. All planes and rotorcraft have some form of camber on their wings. There are no aircraft that have flat wings. Many sag to allow the wings to absorb some turbulence on commercial jet liners. The fighter planes do not have the sagging wings because they have to be more rigid to handle the higher G forces. The Venturi Chamber is helpful at understanding the pressure gradient and its lifting characteristics.
2006-11-13 15:16:16 · answer #6 · answered by ANSAG 2 · 1⤊ 1⤋
If they are flat, the leading edge has to push it's way through the atmosphere requiring more energy.
With the wings being curved, the leading edge offers some resistance but it is now used to redirect the air so that there is last drag and at the same time it helps to keep the wing aloft.
Basically the wing shape redirects resistance.
2006-11-13 07:04:28 · answer #7 · answered by Anonymous · 0⤊ 1⤋
This is normal shape of all aircraft wings, becuase flat surface can not create lift (the force that cause aircraft go up ),the curveture of wing cuases any kind of plane to fly .
2006-11-13 08:08:21 · answer #8 · answered by Reza k 1 · 0⤊ 1⤋
A completely flat wing would direct the flow of air away from the ailerons and make it almost impossible to steer.
2006-11-13 07:03:01 · answer #9 · answered by Anonymous · 0⤊ 1⤋
Because more air needs to go under the wing than on top all planes are like that or else they wont fly
2006-11-13 21:40:08 · answer #10 · answered by bill f 3 · 0⤊ 2⤋