飛機飛行原理

Actually, the plane applied the Bernoulli’s Principle
The following is the detail...

Wings

We shall start by looking at a wing cross-section designed as it was meant to be used - to produce lift on an aeroplane. As the wing moves through the air it splits the air into two streams. One stream travels over the wing and one travels under the wing. Because of the way the wing is shaped, the distance across the top of the wind is greater than the distance across the bottom of the wing. This causes the air flowing over the wing to move faster than the air flowing under it.

As we have seen above, Bernoulli’s equation states that a faster moving fluid has a lower pressure than a slower moving one. This means that the faster moving air above the wing has a lower pressure than the air flowing under it. This pressure difference causes the wing to move towards the area of low pressure i.e. in an upwards direction. This phenomenon is known as lift and this is what keeps planes from falling from the sky. The lift on a wing is proportional to its’ area - the larger the area, the more lift is produced.

An inverted wing is used on racing cars. An inverted wing is basically a standard wing fitted upside-down. This means that the lift that is produced is in the opposite direction to a standard wing - this type of lift is known as ‘negative lift’, otherwise known as downforce. This downforce forces the car onto the road which in turn forces the tyres down onto the road with a lot more force than the weight of the car alone. The grip that tyres can produce increases roughly in a linear manner with increasing load (downforce in this case). Therefore with the increase in downforce, the load on the tyres increases meaning that the grip the tyres have is increased proportionately. This allows the drivers to go faster around corners than in a car without the downforce and produces significant time savings.

Usually, two wings are used - one at the rear and one at the front. This is done to balance the forces so that the grip is roughly equal at both ends of the car otherwise the handling of the car would be terrible, especially at higher speeds when maximum downforce is achieved.

Fixed-wing aircraft include a large range of craft from small training and recreational aircraft to large airliners and military cargo aircraft. Some aircraft use fixed wings to provide lift only part of the time and may or may not be referred to as fixed-wing.
The term also embraces aircraft with folding wings that are intended to fold when on the ground. This is usually to ease storage or facilitate transport on, for example, a vehicle trailer or the powered lift connecting the hangar deck of an aircraft carrier to its flight deck. It also embraces "variable geometry" aircraft, such as the General Dynamics F-111, Grumman F-14 Tomcat and the Panavia Tornado, which can vary the sweep angle of their wings during flight. There are also rare examples of aircraft which can vary the angle of incidence of their wings in flight, such the F-8 Crusader, which are also considered to be "fixed-wing".


An F-16 Fighting Falcon, a military fixed-wing aircraft

Two necessities for all fixed-wing aircraft (as well as rotary-wing aircraft) are air flow over the wings for lifting of the aircraft, and an open area for landing. The majority of aircraft, however, also need an airport with the infrastructure to receive maintenance, restocking, refueling and for the loading and unloading of crew, cargo and/or passengers. While the vast majority of aircraft land and take off on land, some are capable of take off and landing on ice, snow and calm water.

The aircraft is the second fastest method of transport, after the rocket. Commercial jet aircraft can reach up to 900 km/h. Single-engined aircraft are capable of reaching 175 km/h or more at cruise speed. Supersonic aircraft (military, research and a few private aircraft) can reach speeds faster than sound. The speed record for a plane powered by an air-breathing engine is currently held by the experimental NASA X-43, which reached nearly ten times the speed of sound.
The biggest aircraft currently in service is Antonov An-225, while the fastest currently in production is the Mikoyan MiG-31. The biggest supersonic jet ever produced and currently in service is Tupolev-160.
Aircraft parts
A typical fixed-wing aircraft can be divided into the following major parts:
· A long cylinder, called a fuselage, with tapered ends to make its shape aerodynamically smooth. The fuselage carries the human flight crew, the passengers if the aircraft is a passenger aircraft, and/or the cargo if the aircraft carries cargo. The pilots, who are members of the flight crew, operate the aircraft from a cockpit located at the front of the fuselage and equipped with windows, controls, and instruments.
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Aircraft controls
A number of fairly standardized controls allow pilots to direct aircraft in the air. The controls found in a typical fixed-wing aircraft are as follows:

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History

Main articles: Aviation history and First flying machine

The dream of flight goes back to the days of pre-history. Many stories from antiquity involve flight, such as the Greek legend of Icarus and Daedalus. Leonardo da Vinci drew an aircraft in the 15th century. With the first flight made by man (Francois Pilatre de Rozier and Francois d'Arlandes) in an aircraft lighter than air, a balloon, the biggest challenge became to create other craft, capable of controlled flight.

When powered flights of the X-34 begin later this year, the experimental vehicle will be carried aloft by the L-1011, then released for rocket-powered flight and a standard horizontal landing. Eventually, the X-34 will perform high-speed suborbital free flights to demonstrate technologies such as advanced thermal protection system, composite structural components and autonomous landing.