Реферат по предмету "Иностранный язык"


The Structure Of An Airplane Essay Research

Paper

The idea of flight has fascinated people for centuries, even to this day, which is why I decided to research on airplanes. When I researched the history on planes, I was surprised at the effort and the time people long ago spent trying to make a machine that flies. I also wondered, like many, how an airplane is able to fly and sustain in the air. Wanting to know the answers to these types of questions I had, gave me the determination to really researched this topic. History of Planes Early History The idea of flying existed from a long time ago. Ancient legends showed numerous references to the possibility of flight. Philosophers believed that it could be achieved by imitating the wing motions of birds. The artist Leonardo Da Vinci sketched ideas on how a man can fly. 19th Century The development of aviation took various paths during the 19th century. The father of aviation, Sir George Cayley was a British aeronautical engineer and inventor. He proved his ideas of flight with experiments involving kites and controlled human-carrying gliders. Charles Augustus Lindbergh was the first person to make a nonstop solo flight across the Atlantic. He made the flight to win the prize of $25,000 offered by Raymond B. Orteig of New York City for the first nonstop transatlantic solo flight between New York City and Paris. In his single-engine monoplane named the Spirit of St. Louis, he left Roosevelt Field at 7:52 AM on May 20, 1927. After a flight of 33 hours 32 minutes, he landed at Le Bourget Airport near Paris. The Wright Brothers On December 17, 1903, near Kitty Hawk, North Carolina, the brothers Wilbur and Orville Wright made the world’s first successful flights in a heavier-than-air aircraft. The brothers had designed, constructed, and flown the airplane. On that day, each brother made two flights. In 1904, the brothers continued the development of their airplanes design and also improved their skill as pilots. They made 105 flights, the longest flight lasting more than 5 minutes. In 1905, their best flight was 24.2 miles in 38 minutes and 3 seconds. On September 9,1908 Wilbur completed the world’s first flight of more than one hour carrying a passenger. On September 17, 1908, the airplane crashed injuring Orville and his passenger Lieutenant Thomas E. Selfridge. Lieutenant Thomas E. Selfridge died hours later from a concussion. Orville continued demonstrations for the Signal Corps in July 1908. By the end of the month he met their requirements and the airplane was purchased on August 2, 1908. It became the first successful military airplane. It stayed in active service for two years. Today it is located at the Smithsonian Institution in Washington, D.C. Principle of Flight Lift Airplanes are able to fly because air moving over and under its surfaces, like its wings, travel at different velocities. It produces air pressure which is high below the wing and low above it. The high pressure pushes and the low pressure pulls. The lift of an airplane depends on the area, shape and tilt of the wing. And on the speed of the aircraft. The area of the wing is significant in causing the lift in an aircraft because, the more the wing is exposed to the air, the greater the lift. Different wing shapes produce a different area. The up or down tilt of the wing is called the angle of attack. As a wing is tilted upward, its angle of attack is increased which also increases the lift. Aircraft speed is also important to the lift of an aircraft. The faster the air moves over and under the surfaces of an airplane, the greater the lift. Drag Drag is the force that slows the motion of the airplane through the air. Drag is often a result of the resistance of air to objects moving through it. Airplane Structure Fuselage A fuselage is the center part of an airplane. In the early days of aviation, the fuselage was simply an open structural mount. It was used to support the other components of the plane and the bottom of the airframe was used as the landing gear. Later on the years, due to the need for greater strength and better performance, an enclosed, box-like fuselage was developed. It is also known as a truss. It not only increased lift and decreased drag, but it also provided protection for the pilot, passengers, and the space for cargo. Wings The structure of a typical wing is composed of a spar-and-rib framework enclosed by a thin covering of metal sheet or treated fabric. Metal is used primarily for larger planes and fabric for smaller ones. Sometimes the wing is covered with bonded plywood or with resin-impregnated glass fiber. The spar is a beam that extends from the fuselage to the wing tip. One or more spars may be used in the wing, but usually a single spar is used. The ribs give the wing its external shape. They are arranged at right angles to the spar. The amount of wings on a plane varies. A single-winged plane is known as a monoplane. The monoplane made its appearance in the first decade of powered flight. In early airplane construction there was the use of two wings on a plane, which is called a biplane. Multiple-wing planes have the advantage of greater lift, but the monoplane has less drag. Cantilever wings are another type. They obtain their entire strength from structural elements inside the skin. The size and shape of wings also vary, depending on specific aerodynamic of the plane. For example, the wings of most supersonic planes are really thin with a knifelike leading edge. This helps to reduce the shock of compression when the plane reaches the speed of sound. Undercarriage (Landing Gear) Components of the undercarriage include the oleo strut, a hydraulic arm connecting the wheel with the wing or fuselage which absorbs the shock of landing, the retracting mechanism which raises and lowers the gear, the wheels, and the wheel brakes. The most commonly known undercarriages are: the conventional two-wheel gear and the tricycle gear. The two-wheel gear consists of two large wheels located forward of the center of gravity of the plane with a small wheel at the tail. A tricycle gear consists of two large wheels behind the center of gravity and a third wheel, called the nosewheel, in front of the two main wheels. The tricycle gear is easier to land because braking and maneuvering are improved.. Other forms of landing gear include a caterpillar tread for handling heavy loads on poor landing fields, a swiveling gear for landing in crosswinds, and a combination ski-wheel gear for use on ice and snow. Tail Assembly Tail assembly consists of two basic surfaces, horizontal and vertical. They each have movable sections providing control and stability of the craft. The leading section of the horizontal surface is called the horizontal stabilizer. The rear movable section is called the elevator. The stationary section of the vertical surface is called the fin. The movable section is called rudder. Tails vary in size according to the type of aircraft. Control Components There are three main control devices, each of which provides for movement about a different axis. The three devices include the movable sections of the tail, which are the elevators and rudders; and the movable sections of the edge of the wing which are called ailerons. The control are operated from the cockpit by a control stick or wheel column and rudder pedals. Stick control is used in smaller, lighter airplanes. The wheel, is generally used in larger airplanes because of its greater leverage. Rudders Rudders provide for turning movement around the vertical axis. It changes the course of the plane to the left or the right. When the right rudder pedal is pressed, the rudder turns the plane to the right around the vertical axis. Pressing the left pedal produces a left turn. Other controls include flaps to increase lift for takeoff or drag for landing. Spoilers are used to impair the lift of the wing. They are surfaces that normally lie flush with the wing but can be raised. A similar surface called an air brake, extends at right angles to the under-surface of the wing to slow the speed of the plane. Ailerons Ailerons control rolling movement around the longitudinal axis. Ailerons are usually placed far out on the wing. Leftward movement of the stick or the wheel raises the left aileron and lowers the right, which moves the plane to the left. The reverse tilt happens when the stick or wheel is moved to the right. Elevators Elevators are used for pitching movement around the lateral axis. A backward pull on the control stick or wheel column raises the elevators, which moves the tail down and lifts the nose of the plane for a climb. Forward movement of the stick or column makes the plane dive. Propulsion Internal Combustion Engines There are two types of internal combustion engines, the reciprocating engine and the compound engine. In the reciprocating engine, heat energy is used to move pistons operating within cylinders. The cylinder arrangement is usually in-line, horizontal-opposed, or radial. They either use air-cooling or liquid-cooling systems. Nearly all aircraft reciprocating engines are gasoline operated. The advantages of the reciprocating engine are reliability and fuel economy. The compound engine consists of a reciprocating engine combined with an exhaust-gas turbine. It drives a supercharger which is an air compressor in the intake system of the engine. The advantage of the compound engine over the reciprocating engine is its high-power capacity at high altitudes. Jet Engines The various types of jet engines include: the turbojet, the turboprop, the ramjet, and the rocket engine. The turboprop and turbofan engines are modifications of the turbojet engine. They are gas turbine engines. The air that enters the intake of the engine is first compressed in a compressor. Fuel is then added to burn the oxygen in the air which increases the gas temperature and its volume. The high pressure gases are then partially expanded through a turbine which drives the compressor. The residual gas is used to produce a high leaving velocity and with it the thrust to move the craft. Turbojet or turbofan engines perform better at higher speeds. The ramjet engine is an internal-combustion engine. The air compression needed for combustion is obtained from the speed of forward motion alone. As in the turbojet its power output is delivered as the jet thrust of its released gases. The ramjet consumes so much fuel that it is used only in guided-missile applications. Types and Uses Commercial Commercial planes are typically used to carry passengers or mail. A type of commercial plane would be the Boeing 727. Military There are four types of military planes: combat, cargo, training, and observation planes. Combat planes are either fighters or bombers for land, sea, and carrier operations. A type of military plane would be the B-1B Bomber and the F-4 Phantom. General General planes are usually used for private pleasure, business, agricultural or other special services. The most common use would be agriculture. Agricultural applications include dusting and spraying insecticides or herbicides, fertilizing, and seeding. This research paper brought me to some interesting places and gave me the opportunity to meet people who had a lot to say about airplanes. I got to talk to people who repair airplanes to people who were ex-pilots in the military. I learned a lot about airplanes, but part of really wanting to know about something is having an interest in it from the beginning.




Не сдавайте скачаную работу преподавателю!
Данный реферат Вы можете использовать для подготовки курсовых проектов.

Поделись с друзьями, за репост + 100 мильонов к студенческой карме :

Пишем реферат самостоятельно:
! Как писать рефераты
Практические рекомендации по написанию студенческих рефератов.
! План реферата Краткий список разделов, отражающий структура и порядок работы над будующим рефератом.
! Введение реферата Вводная часть работы, в которой отражается цель и обозначается список задач.
! Заключение реферата В заключении подводятся итоги, описывается была ли достигнута поставленная цель, каковы результаты.
! Оформление рефератов Методические рекомендации по грамотному оформлению работы по ГОСТ.

Читайте также:
Виды рефератов Какими бывают рефераты по своему назначению и структуре.

Сейчас смотрят :

Реферат Социально-педагогическая деятельность с детьми оставшимися без попечения родителей
Реферат Чалдыранская битва
Реферат Индуизм древнейшая национальная религия Индии
Реферат Конвоирование осужденных к лишению свободы (содержание, правовое регулирование, проблемы совершенствования)
Реферат Принцип состязательности в гражданском процессе
Реферат Safety Problems In America Essay Research Paper
Реферат Основы организации учета затрат и калькулирование себестоимости продукции, работ, услуг
Реферат Дефекты правового правосознания юристов
Реферат 1. Предмет, задачі та значення психології в сучасному суспільстві
Реферат Потребительские свойства косточковых плодов
Реферат Беспредметное искусство
Реферат Преобразования Лоренца постоянство скорости света и требование однородности времени
Реферат Эпоха Петра 1: рождение русского флота
Реферат Проведение внеклассного мероприятия на тему: "Конституция РФ"
Реферат Становление основных институтов гражданского общества в России