- October 8, 2012
- Posted by: essay
- Category: Term paper writing
Our way of traveling was changed because of the airplane. After lots of attempts to create an airplane failed because of lack of knowledge in physics, the Wright Brothers changed history with their first successful piloted heavier-than-air flying machine in December 17, 1903.
Nowadays we’ve got used to airplanes to such extent, that we don’t even lift up our heads when we hear this familiar roaring.
And though everybody knows, how an airplane looks like, far not everybody knows how it is engineered, why it flies, and which physical laws are used for that. A contemporary airliner represents a complicated system, which is created due to achievements of physics, structural mechanics and aerodynamics (“Airplane”¯ Encarta encyclopedia, 2003).
There are four primary forces that are acting upon an airplane.
First, it is lift caused by the wings and their flaps by pushing air downward and upward. The second force is weight that offsets lift, because it acts in the opposite direction. The weight has to be overcome by the lift for a plane to be able to rise upward. The third one is thrust, which propels an airplane forward through the air. It is created by the plane’s propulsion system, which is either a propeller or jet engine. Finally, it is drag, which is created because any object, moving through air, produces friction, because it’s trying to move fluid or air out of its way. The faster a plane is the less drag it should have. (“Airplane,”¯ Encarta encyclopedia, 2003)
An airplane carries itself in flight by deflecting the passing air stream towards the earth and at the same time the air stream reacts by pushing the wings upward. This is a simple example of Newton’s third law of motion which states that “the second object must push back on the first object with a force of equal strength pointing in the opposite direction.”¯
So, wings are a key part in the construction of an airplane, they generate carrying capacity: wing’s mould is engineered so that a console divides the blast running on an airplane, and the airstreams are split over and under the wing (Heppenheimer, 2004).
Wing’s bottom surface is flat, and its upper one is saddle-backed; therefore the air flows around the topside with a greater speed, than round the bottom of the wing. There forms a low-pressure area above a wing, which “pulls”¯ upwards a wing and whole plane in addition; and simultaneously a high-pressure area is formed under a wing. Thus, ascentional force appears (Heppenheimer, 2004).
The great number of smaller bending consoles are mounted on wings: wing flaps, wing slats, spoilers, ailerons, dash boards, etc. They allow regulating the airplane’s movement in three subspaces, ground-speed, and some other parameters of flight.
When wing flaps are extended, camber of a profile and wing surface area increase; and consequently, ascentional force increase too. In addition, flap extension contributes to the increase of aerodynamic resistance. Wing flaps can consist of a few sections, forming 1-3 cracks, which make airstream overflow from the bottom surface to the upper one, dispersing it. 15Ā° flap extension increases ascentional force with relatively low increase of resistance; further extension makes resistance increase considerably quicker than ascentional force grows. As a rule, wing slats automatically bend simultaneously with wing flaps, but they can also be controlled independently. The effect of wing slats consists in the increase of possible incidence angle, so that a shock stall from the topside of wing takes place at a bigger incidence angle.
The symmetric involving of wing spoilers results in the sharp diminishing of ascentional force and braking of airplane. An airplane starts braking due to growing resistance and smoothly drifts down landing. Spoilers not so much reduce the speed directly, as reduce wings’ ascentional force, which results in the increase of loading on wheels and the improvement of their tripping of with surface (Bloomfield, 2003).
On the back edge of a wing there are ailerons, small mobile panels by which the rolling motion of an airplane is regulated. Under a wing, dash boards are located, which are bending downward panels intended for the increase of stability and dirigibility of a machine during lifting-off and landing. At flight they are released on a small corner, and at landing they are fully release in order to decrease the speed. (“Airplane,”¯ Encarta encyclopedia, 2003)
Often vertical wingtips are also placed on wings which diminish air eddies on wing tails, reducing the level of vibration, and, as a result, saving fuel. Aerodynamic properties of a wing are determined by its wing spread, area, and sweep corner.
Apart from wings, most planes have a mechanical tail which also works as a stabilizer. When the plane is turning or banking is keeps this process as stabilized as possible. In fuselage tail section a tail fin, stabilizer, diving-rudder and vertical rudder are located. All together these elements form fin assembly, which makes an airplane stable at flight. A tail fin regulates stability of a plane on the axis of motion; and stabilizers, which in most cases resembles wings by their construction, control plane’s tangage (Bloomfield, 2003).
Besides, an airplane includes landing gears, chassis, which are brakes and tires designed specifically for the demands of flight. Tires must be capable of going from a standstill to nearly 200 mph at landing, as well as carrying nearly 400 metric tons. Brakes are special heat-resistant materials, which are able to stop a 400-metric-ton airliner aborting a takeoff at the last possible moment (Bloomfield, 2003). However, chassis could be a great burden at flight, because they create superfluous resistance reducing the speed. Therefore, practically all modern airplanes are constructed with build with contractile undercarriage.
For modern airplanes turbojet or turboprop engines are characteristic. The simplified scheme of ramjet looks the following way: a turbine revolves a ventilator, which disperses blast, entering combustion chambers. Here it interfuses with fuel from a tank; mixture burns; and gas mass, which considerably exceeds mass of the air entering an engine, appears. Breaking forth outside, the stream of hot gas creates traction, setting an airplane in motion (Bloomfield, 2003).
Commercial airlines are probably one of the top ideas in the 20th century. After the Wright Brothers made history in their first flight, the next question was how to transport people to different locations. One of the first problems that came about was how will people breathe inside the cabin (Heppenheimer, 2004). The air we breathe inside an airplane is pumped by the jet engines. The jet engine has a compressor that takes the low density air outside and boosts its pressure and density. Some of this air is then redirected to the cabin after passing through an air conditioner to cool the air. (Bloomfield, 2003)
The concept of the Airplane is based a lot on the information in Chapter 2 in our physics book which deals with time, velocity, and motion in a constant straight line. I will say that 85% of the way a plane flies has to do with physics, and how you can manipulate gravity and other forces in the earth. The Wrights brothers recognized the idea and engineered the perfect introduction of an airplane.
Finally, our lives have become easier thanks to the invention of the airplane. We are capable of flying to any part of the world in matter of hours. In early history we used railroads which took hours just for a short distance. Nowadays airplanes even play a big factor in War fair.
Even mail is capable of being sent and received in a couple of days all across the world. Thanks to Newton laws and the Wright brothers who had the ambition to create the first piloted plane.