Can someone explain how aeroplanes fly? I am looking for the principle behind its flight.?

Answer 1

In heavier-than-air aircraft, there are two ways to produce lift: aerodynamic lift and engine lift. In the case of aerodynamic lift, the aircraft is kept in the air by wings or rotors (see aerodynamics). With engine lift, the aircraft defeats gravity by use of vertical thrust. Examples of engine lift aircraft are rockets, and VTOL aircraft such as the Hawker-Siddeley Harrier.

Among aerodynamically lifted aircraft, most fall in the category of fixed-wing aircraft, where horizontal airfoils produce lift, by profiting from airflow patterns determined by Bernoulli's equation and, to some extent, the Coanda effect.

The forerunner of these type of aircraft is the kite. Kites depend upon the tension between the cord which anchors it to the ground and the force of the wind currents. Much aerodynamic work was done with kites until test aircraft, wind tunnels and now computer modelling programs became available.

In a "conventional" configuration, the lift surfaces are placed in front of a control surface or tailplane. The other configuration is the canard where small horizontal control surfaces are placed forward of the wings, near the nose of the aircraft. Canards are becoming more common as supersonic aerodynamics grows more mature and because the forward surface contributes lift during straight-and-level flight.


A collection of NASA testing aircraftThe number of lift surfaces varied in the pre-1950 period, as biplanes (two wings) and triplanes (three wings) were numerous in the early days of aviation. Subsequently most aircraft are monoplanes. This is principally an improvement in structures and not aerodynamics.

Other possibilities include the delta-wing, where lift and horizontal control surfaces are often combined, and the flying wing, where there is no separate vertical control surface (e.g. the B-2 Spirit).

A variable geometry ('swing-wing') has also been employed in a few examples of combat aircraft (the F-111, Panavia Tornado, F-14 Tomcat and B-1 Lancer, among others).

The lifting body configuration is where the body itself produce lift. So far, the only significant practical application of the lifting body is in the Space Shuttle, but many aircraft generate lift from nothing other than wings alone.

A second category of aerodynamically lifted aircraft are the rotary-wing aircraft. Here, the lift is provided by rotating aerofoils or rotors. The best-known examples are the helicopter, the autogyro and the tiltrotor aircraft (such as the V-22 Osprey). Some craft have reaction-powered rotors with gas jets at the tips but most have one or more lift rotors powered from engine-driven shafts.

A further category might encompass the wing-in-ground-effect types, for example the Russian ekranoplan also nicknamed the "Caspian Sea Monster" and hovercraft; most of the latter employing a skirt and achieving limited ground or water clearance to reduce friction and achieve speeds above those achieved by boats of similar weight.

A recent innovation is a completely new class of aircraft, the fan wing. This uses a fixed wing with a forced airflow produced by cylindrical fans mounted above. It is (2005) in development in the United Kingdom.

And finally the flapping-wing ornithopter is a category of its own. These designs may have potential but currently have no major practical applications.

Answer 2

The principle is Bernoulli's Principle, which states that the total energy within the fluid remains the same, if there is increase in the velocity of the fluid than this must be accompanied by reduction in pressure energy, in other words if velocity of fluid increases its pressure decreases. The wings of the aircraft are designed in such a way that there is a tilt downwards, because of this the air over the topside of the wing initially travels at higher velocity and as area increases its velocity reduces, which increases the pressure. Now this pushes the back part of the wing downwards as compared to front side and the wings gets tilted. The propeller or jet engine of the plane either sucks itselfs or pushes itself thus creating thrust, and hence the plane is able to move forward as well as climb due to a phenomena called as lift. Hope you got the concept

Answer 3

Before any heavier than air aircraft could successfully fly, several people studied the way birds fly. Birds fly by flapping their wings and thereby pushing the air down. The air applies equal and opposite force on the wings of a bird and that is how the bird's weight is sustained by this force, called lift.

In aeroplanes, this force is created by wings but not by flapping action. It is created by providing the cross sectional area of the wing as an aerofoil (An aerofoil is an efficient lifting device.).

The shape of an aerofoil is such that it creates lower pressure on the top surface of the wing and higher pressure on the lower surface of the wing. This differential pressure gives rise to the same force, lift. The lift sustains the weight of the aircraft and prevents it from falling. And as for forward motion, the engine provides thrust to move the aeroplane in the forward direction.

Answer 4

The wing's angle of attack -- how much it's tilted front-up from the horizontal -- defines how much the wing pushes air down and the wing (and airplane) gets pushed up. All the answers about the Bernoulli flow principles given above are true -- and that's the way it's taught in schools -- but that doesn't explain how the plane stays up. The Bernoulli flow characteristics don't make enough pressure difference between top and bottom of wing to lift the plane. It really comes down to "the wing pushes the air down and gets pushed up as a result."
The book _Understanding Flight_ by David Anderson and Scott Eberhardt discusses this.

Answer 5

F = m a

Downward Force on the air (holding the plane up) =
mass of air * downward acceleration of air

When air (or any fluid) passes over an airfoil, the shape of the foil and the properties of aerodynamics cause the air flow (on both the top and the bottom of the foil) to change direction at a downward angle. This change in direction (and perhaps the change in speed of the air as well, although not necessarily required), result in a change in the "velocity vector" of the air. By definition, the rate of change of velocity is an acceleration (even if only the direction changes and the speed does not).
Newton's Law of motion is: F = m a ...
(note: F and a are vector quantities meaning they have a direction as well as a magnitude associated with them.)
A downward change in the velocity, or equivalently, a downward acceleration of the air necessarily requires a downward force on the air. However, the net force on the plane must be zero (if the plane is flying at constant velocity). Thus, to balance the downward force on the air, there is an upward force on the wing, aka lift.
One can also look at it in terms of change in momentum and impulse, by taking the time-derivative of F = ma. Thus when you kick a soccer ball, it's momentum is changed by applying a force for a period of time.

It's not as complicated as it sounds, it's just not that easy to explain it well in words, that's why people tend to give simplified answers to this question, and it's easy to misinterpret and be misled by a simple answer to a complex question.

Answer 6

The answer is a thing called lift that causes the airplane to fly upwards. The wing of an airplane is shaped in such a way to make the air travel over the more lengthy section of wing, and when that happens it will lift the wing.

Take a regular piece of paper, hold it in the middle of the shorter section, so it hangs downward ( looks like a cain) and blow on the paper near your fingers. Instead of the paper hanging straight down, it comes up at an angle.

Thats lift.

Answer 7

Yay for my 3000 level fluids course.

Wings of a plane are shaped so that it's a longer path for air to travel over the wing than under it. This means that the air going over the wing has to be going faster than the air going under the wing. According to the Beroulli principle, when air speeds up, its pressure is lowered. So this means that the pressure above the wing is lower than below the wing. The pressure difference acts as a force lifting the plane up, and this lets it fly.

Answer 8

As the plane moves forward the wings create a pressure difference that causes the plane to rise. The pressure on the top part is less.

Answer 9

Its called aerodynamics.