外文翻譯--飛機(jī)的介紹

南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 1 頁(yè) 附錄 外文資料及譯文 1.外文資料 : An Introduction to the Airplane Airplanes come in many different shapes and sizes depending on the mission of the aircraft, but all modern airplanes have certain components in common. These are the fuselage, wing, tail assembly and control surfaces, landing gear, and powerplant(s). For any airplane to fly, it must be able to lift the weight of the airplane, its fuel, the passengers, and the cargo. The wings generate most of the lift to hold the plane in the air. To generate lift, the airplane must be pushed through the air. The engines, which are usually located beneath the wings, provide the thrust to push the airplane forward through the air. The fuselage is the body of the airplane that holds all the pieces of the aircraft together and many of the other large components are attached to it. The fuselage is generally streamlined as much as possible to reduce drag. Designs for fuselages vary widely. The fuselage houses the cockpit where the pilot and flight crew sit and it provides areas for passengers and cargo. It may also carry armaments of various sorts. Some aircraft carry fuel in the fuselage； others carry the fuel in the wings. In addition, an engine may be housed in the fuselage. The wing provides the principal lifting force of an airplane. Lift is obtained from the dynamic action of the wing with respect to the air. The cross-sectional shape of the wing as viewed from the side is known as the airfoil section. The planform shape of the wing (the shape of the wing as viewed from above) and placement of the wing on the fuselage (including the angle of incidence), as well as the airfoil section shape, depend upon the airplane mission and the best compromise necessary in the overall airplane design. 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 2 頁(yè) The control surfaces include all those moving surfaces of an airplane used for attitude, lift, and drag control. They include the tail assembly, the structures at the rear of the airplane that serve to control and maneuver the aircraft and structures forming part of and attached to the wing. The tail usually has a fixed horizontal piece (called the horizontal stabilizer) and a fixed vertical piece (called the vertical stabilizer). The stabilizers provide stability for the aircraft they keep it flying straight. The vertical stabilizer keeps the nose of the plane from swinging from side to side (called yaw), while the horizontal stabilizer prevents an up-and-down motion of the nose (called pitch). (On the Wright brothers first successful aircraft, the horizontal stabilizer was placed in front of the wings. Such a configuration is called a canard after the French word for duck). The hinged part found on the trailing edge of the wing is called the aileron. It is used to roll the wings from side to side. Flaps are hinged or pivoted parts of the leading and/or trailing edges of the wing used to increase lift at reduced airspeeds, primarily at landing and takeoff. Spoilers are devices used to disrupt the airflow over the wing so as to reduce the lift on an airplane wing quickly. By operating independently on each wing, they may provide an alternate form of roll control. Slats at the front part of the wing are used at takeoff and landing to produce additional lift. At the rear of both the aileron surfaces and elevators and rudders are small moving sections called trim tabs that are attached by hinges. Their function is to (1) balance the airplane if it is too nose heavy, tail heavy, or wing heavy to fly in a stable cruise condition； (2) maintain the elevator, rudder, and ailerons at whatever setting the pilot wishes without the pilot maintaining pressure on the controls； and (3) help move the elevators, rudder, and ailerons and thus relieve the pilot of the effort necessary to move the surfaces. The landing gear, or undercarriage, supports the airplane when it is resting on the ground or in water and during the takeoff and landing. The gear may be fixed or retractable. The wheels of most airplanes are attached to shock-absorbing struts that use oil or air to cushion 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 3 頁(yè) the blow of landing. Special types of landing gear include skis for snow and floats for water. For carrier landings, arrester hooks are used. Forward motion, or thrust, is generated by a thrust-producing device or powerplant to sustain flight. The powerplant consists of the engine (and propeller, if present) and the related accessories. The main engine types are the reciprocating (or piston type), and the reaction, or jet, engine such as the ram jet, pulse jet, turbojet, turboprop, and rocket engine. The propeller converts the energy of a reciprocating engines rotating crankshaft into a thrust force. Usually the engines are located in cowled pods hung beneath the wings, but some aircraft, like fighter aircraft, will have the engines buried in the fuselage. Other configurations have sometime been used. For instance, the Wright brothers 1903 Flyer had pusher propellers (propellers at the rear of the plane) and the elevators at the front of the aircraft. Many fighter aircraft also combine the horizontal stabilizer and elevator into a single stabilator surface. There are many possible aircraft configurations, but any configuration must provide for the four forces needed for flight. Airfoil An airfoil is any part of an aircraft that is designed to produce lift. The wing is the primary airfoil but the propeller can also be an airfoil as well as the tail surfaces or sometimes even the fuselage itself. An airfoil has a leading edge, a trailing edge, a chord, and camber. The leading edge is the front of the airfoil the portion that meets the air first. The trailing edge is the back of the airfoil the place at which the airflow over the upper surface of the airfoil joins the airflow over the lower surface of the airfoil. 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 4 頁(yè) The elements of an airfoil The chord of an airfoil is the imaginary straight line drawn through the airfoil from its leading edge to its trailing edge. The camber of an airfoil is the curve of its upper and lower surfaces. This curve is measured by how much it departs from the chord of the airfoil. Some airfoils have very little camber, i.e., the airfoil looks flat, while others have a higher degree of camber the airfoil has more curve. The term upper camber refers to the camber of the upper surface of the airfoil. The term lower camber refers to the camber of the lower surface of the airfoil. The camber of an airfoil affects its lift. The direction of the air that is flowing past an airfoil relative to the path of flight is called the relative wind. The relative wind is always parallel and opposite in direction to the path of flight. Landing Gear Landing gear is the structure under a planes fuselage that allows it to land safely. The earliest landing gear consisted of skids, but designers soon attached wheels to the skids. Landing gear must have some mechanism for absorbing the force of the landing in addition to the airplanes weight. Early gear used flexible material for landing gear struts (the structure that connected the airframe and the wheels). Some landing gear use a shock absorbing system called the oleo strut that cushions the landing and keeps the plane level while landing. There are several types of landing gear: Conventional landing gear consists of two wheels forward of the aircrafts center of gravity and a third, smaller wheel at the tail. This small wheel can turn in any direction. This configuration has the nickname the taildragger because, when the plane is on the ground, the tail of the plane is closer to the ground than the forward end. 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 5 頁(yè) Tricycle landing gear consists of a forward (nose) wheel and a pair of wheels located midway on the fuselage. The nose gear is steerable by means of the rudder pedals. Tandem landing gear (also called bicycle landing gear) consists of a main gear of two sets of wheels set one behind the other. Landing gear can be either fixed or retractable. Often, smaller, less expensive planes have fixed landing gear-landing gear that remains exposed when the plane is flying-because it is less costly to build and maintain. Retractable landing gear can be retracted into the body of the plane. This feature gets the structure out of the airflow and reduces drag. Aircraft that have to land on water are fitted with pontoons rather than wheels. Some planes had interchangeable pontoons and wheels so that the plane could be used to land both on land and on water. Four Forces of Flight The four forces of flight are lift, drag, thrust, and weight. Lift is the upward force created by the wings moving through the air that sustains the airplane in flight. Lift operates to overcome weight. It must be equal to or greater than the weight of the object in flight and acting in the opposite direction. Lift can be increased by increasing the forward speed of the aircraft or by increasing the angle of attack Drag is the resistance of the airplane to forward motion. It is directly opposed to thrust and is caused by the resistance of air. Thrust is the force exerted by the engine and its propeller(s). It pushes the air backward with the object of causing movement of the airplane in the forward direction. Weight is the downward force due to the weight of the airplane and its load. It is directly opposed to lift 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 6 頁(yè) An aircraft is in a state of equilibrium when the thrust and drag are equal and opposite. It will continue to move forward at the same uniform speed. If thrust or drag becomes greater than the opposite force, the aircraft loses its state of equilibrium. If thrust is greater than drag, the aircraft will accelerate. If drag is greater than thrust, the aircraft will lose speed and eventually descend. When lift and weight are equal and opposite, the airplane is in a state of equilibrium. If lift is greater than weight, the aircraft will climb. If weight is greater than lift, the airplane will descend. The four forces of flight Streamlining Streamlining is the shaping of an object, such as an aircraft body or wing, to reduce the amount of drag or resistance to motion through a stream of air. A curved shape allows air to flow smoothly around it. A flat shape fights air flow and causes more drag or resistance. Streamlining reduces the amount of resistance and increases lift. To produce less resistance, the front of the object should be well rounded and the body should gradually curve back from the midsection to a tapered rear section. 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 7 頁(yè) Streamlining reduces the amount of resistance experienced by an airfoil Angle of Incidence The angle of incidence is the angle between the aircrafts longitudinal axis and the chord of the wing. The angle of incidence is the angle at which the wing is fixed to the aircrafts fuselage. It is the angle formed by the chord of the airfoil and the longitudinal axis of the aircraft.This longitudinal axis of the aircraft is the imaginary line drawn through the fuselage from the front of the aircraft to the rear of the aircraft. 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 8 頁(yè) Usually, the angle of incidence is the angle formed between the wing and the longitudinal axis of the aircraft body. Flight Control Surfaces The rudder, elevator, and aileron are the primary control surfaces on an airplane. The rudder controls the airplanes yaw, the elevator controls its pitch, and the aileron controls its roll (see the individual dictionary entries for each of these.) Others are addressed below. Wing flaps are a movable part of the wing, normally hinged to the trailing edge (rear edge) of each wing closest to the airplane body. The pilot extends and retracts the flaps. Extending the flaps increases the wing camber and the angle of attack of the wing. This increases wing lift and also increases drag. Flaps enable the pilot to make a steeper descent when landing without increasing airspeed. They also help the airplane get off the ground in a short distance. There are many different types of flaps. Some hinge, some slide, some open with slots, and some help smooth the air over the wing even when high angles of attack are flown during landing. Slats are protrusions from the leading edge (front edge) of a wing. They add to the lift of a wing. Slats and flaps work together to maintain laminar flow (a smooth airflow) over the top of the wing. Spoilers reduce lift. Spoilers are found along the top of the wing. When they arent being used, they fit into or flush with the wings surface. When they are used, they protrude from the wings surface 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 9 頁(yè) into the airflow and destroy the laminar flow for a portion of the wing. The size of the spoiler varies according to how much lift is to be spoiled. Different spoiler designs are found on different types of planes, but their function is the same. Some devices only produce drag without affecting the wings lift. These include speed brakes, air brakes, dive flaps, or drag parachutes. They may be located on the wings trailing edge or may protrude from the fuselage. These devices allow very steep descents and rapid changes in airspeed. The pilot can stop their effect almost instantaneously by retracting the devices Axes of Rotation An aircraft has three axes of rotation: vertical, lateral, and longitudinal. Credits - Civil Air Patrol 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 10頁(yè) In addition to moving forward, aircraft move about three axes in response to three forces: lift, drag, and side force. These axes can be visualized as three rods that pass through the aircraft so that each intersects the other two. The point of intersection is called the center of gravity. Each of these axes is also perpendicular to the other two. The axis that extends lengthwise through the nose and tail is called the longitudinal axis. Rotation about this axis is called roll. Drag is the force that acts along this axis, but in the opposite direction of the flight path. The axis that extends crosswise from wingtip to wingtip is called the lateral axis. Rotation about this axis is called pitch. Side force acts along this axis. The axis that passes vertically through the center of gravity when the aircraft is in level flight is called the vertical axis. Rotation about this axis is called yaw. Lift acts along this axis. Movement of the ailerons produces changes in roll. Movements of the rudder produce changes in yaw. Movements of the elevator cause changes in pitch. Ailerons The ailerons are one of three primary flight control surfaces found on aircraft. They are movable surfaces that control movement about the longitudinal axis-called roll. The ailerons are used along with the rudder to make turns 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 11 頁(yè) . Movement of the ailerons controls movement of the aircraft around its longitudinal axis. One aileron is found at the outer trailing edge of each wing. They impart a rolling motion to the aircraft, making banking possible. Lowering the aileron on one wing raises the aileron on the other. The wing with the lowered aileron rises because of its increase lift, and the wing with the raised aileron moves downward because of its decreased lift. Thus, the effect of moving either aileron is aided by the simultaneous and opposite movement of the aileron on the other wing. Rods or cables connect the ailerons to each other and to the control stick in the cockpit of the plane. Pushing the control stick to the right moves the right aileron up and the left aileron down. This causes the right wing to dip and helps turn the plane to the right. A downward motion of the aileron increases the camber, thus increasing lift and raising the wing. The right aileron moves upward and decreases the camber on the right wing, resulting in reduced lift. Decreased left on the right wing and increased lift on the left wing cause a roll and bank to the right. Trim and Balance Trim refers to balancing an aircraft in flight around its center of gravity. The center of gravity is the point at which an airplane would balance if it were suspended at that point. Balance is important to airplane stability and safety in flight. 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 12頁(yè) The prime concern of airplane balancing is the fore and aft (front and rear) location of the center of gravity along the longitudinal axis. Location of the center of gravity with reference to the lateral axis is also important. For each item of weight existing to the left of the fuselage centerline, there is an equal weight existing at a corresponding location on the right. This may be upset, however, by unbalanced lateral loading and adverse effects will arise from a laterally unbalanced condition. The pilot can compensate for the resulting wing-heavy condition by adjusting the aileron trim tab or by holding a constant aileron control pressure. However, this places the airplane controls in an out-of-streamline condition, increases drag, and results in decreased operating efficiency. Trim tabs are small surfaces that mechanically or electronically manipulate the rudder, elevator, and ailerons to help stabilize the plane. Trim tabs free the pilot from constantly adjusting the controls. The center of gravity depends on the distribution of weight in the airplane and changes as load items (such as fuel) are shifted or expended. If the center of gravity is displaced too far forward on the longitudinal axis, a nose-heavy condition will result. Conversely, if the center of gravity is displaced too far aft, a tail-heavy condition will result. An unfavorable location of the center of gravity could produce such an unstable condition that the pilot could not control the airplane. The airplane manufacturer sets the fore and aft limits for the location of the airplanes center gravity. Elevators Elevators are one of three primary flight control surfaces found on an airplane. The elevators control the movement of the airplane about its lateral axis. This motion is called pitch. The elevators form the rear part of the horizontal tail assembly and are free to swing up and down. They are hinged to a fixed surface the horizontal stabilizer. Together the horizontal stabilizer and the elevators form a single airfoil. A change in the elevators position modifies the camber of the airfoil, increasing or decreasing lift. 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 13頁(yè) The elevators are connected to the control stick by control cables. Pushing the stick forward moves the elevators downward. This increases the lift produced by the horizontal tail surfaces and causes the nose to drop. Pulling back on the stick causes the elevators to move upward, decreasing the lift produced by the horizontal tail surfaces and forcing the nose upward. The elevator on an aircraft controls the movement of the aircrafts tail. Rudder The rudder is one of three primary flight control surfaces found on an airplane. It is a movable surface hinged to the fixed surface that is located at the rear of the aircraft called the vertical stabilizer, or fin. The rudder controls movement of the airplane about its vertical axis and causes the airplanes nose to move to the right or left and point in a different direction. This motion is called yaw. Control cables connect the rudder to the rudder pedals. Pushing down the right rudder pedal moves the rudder to the right and causes the plane to turn to the right. Pushing down the left rudder pedal turns the plane to the left. The rudder controls the movement of the aircraft around its vertical 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 14頁(yè) axis. Internal Combustion or Reciprocating Engine Another name for a reciprocating engine is an internal-combustion engine. It has this name because the fuel burns inside the engine. It is also often called a piston engine because it has pistons as one of its parts. The major parts of an internal combustion engine are (1) the cylinders, (2) the pistons, (3) the connecting rods, (4) the crankshaft, (5), intake and exhaust valves, (6), the spark plugs, and (7) a valve operating mechanism-also called a cam. Reciprocating engines require fuel, air, compression, and a source of combustion to function. In a modern airplane engine, air mixed with gasoline is drawn into a cylinder, then compressed by a piston moving up and down inside a chamber called a cylinder. A spark from a spark plug ignites the mixture of fuel and air. This causes an explosion that drives the piston downward, creating power. Then the exhaust valve opens and the burned-up gases are pushed past the valve into an exhaust pipe by the piston. Then the process starts over again. This happens hundreds of times a minute. This process is called a four-stroke operating cycle. Parts of a reciprocating engine. Four-stroke five-event cycle. 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 15頁(yè) Jet Engines Jet engines operate on the application of Newtons third law of motion: for every action there is an equal and opposite reaction. The most common type of jet engine is the turbojet engine. Air from the atmosphere enters the fan section at the front of the engine where it is compressed in the compressor section. Then it is forced into combustion chambers where fuel is sprayed into it and ignited. Gases that form expand rapidly and are exhausted out the rear of the combustion chambers. The energy from these gases spins the fan-like set of blades called a turbine, which rotates the turbine shaft. This shaft, in turn, rotates the compressor, thereby bringing in a fresh supply of air through the intake at the front of the engine. The rest of the energy is expelled out the tail pipe, providing forward thrust. Adding an afterburner section, where extra fuel is sprayed into the gases as they are exhausted and the fuel burns, adds thrust. In a turboprop engine, the exhaust gases rotate a propeller that is attached to the turbine shaft. The propeller provides increased fuel economy at lower altitudes. Another type of turbine engine, called a turbofan or bypass engine, uses a fan to produce additional thrust. This is most efficient at high altitudes. The fourth type of jet engine is the ramjet. The ramjet is a simple engine that lacks a turbine and compression chambers. Ramjets do not function at speeds below the speed of sound, although there are new variations of these called SCRAMjets that are designed to generate supersonic speeds. The engine must be on an aircraft already traveling above the speed of sound (supersonic speed) before it can be used. Supersonic air enters the front of the ramjet and is automatically compressed due to the shape of the engines opening. This compressed air is mixed with fuel in the combustion chamber and ignited, causing the resulting gases and energy to be expelled out of the back and providing forward thrust. 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 16頁(yè) A rocket engine operates on the same principle as a jet engine but carries its oxygen with it rather than using oxygen from the atmosphere. Engine Cowling The engine cowling is a removable metal covering that houses the engine and sometimes also a portion of the fuselage of an aircraft. It enables the aircraft to fly more efficiently because it reduces the amount of drag it creates. The NACA low-drag engine cowling was invented by Fred Weick, an engineer from the National Advisory Committee for Aeronautics, in 1928. Cowlings are sometimes also used to enclose landing gear. Propeller Configurations Aircraft have had two types of propeller configurations: pusher propellers and tractor propellers. Aircraft with pusher propellers place the propeller assembly behind the engine. The thrust produced by the propeller pushes the airplane forward. Most of the Wrights planes used this type of configuration. The U.S. Army banned this type of propeller configuration in late 1914 after several pilots died in crashes of planes of this type. The Vultee XP-54 is an example of an aircraft with a pusher propeller. Notice that the propeller is located behind the fuselage. 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 17頁(yè) Credits - U.S Air Force The concept was revived briefly during World War II when the Army Air Corps received designs for a pusher-type aircraft as part of a design competition. In these planes, the propeller was mounted behind the pilot. They appeared to offer better visibility, less drag, and the opportunity to carry more guns in the nose. Three such pusher designs were actually flight tested the Vultee XP-re, Curtiss XP-5, and Northrop XP-56. None went into production. The Blriot monoplane was an early aircraft with a tractor propeller Tractor aircraft have the engine and propeller at the front of the aircraft where the thrust draws or pulls the airplane. Modern aircraft use this type of configuration. the History of Flight The invention of the airplane was a fundamental turning point in history. It redefined the way we fought our wars； revolutionized travel and commerce； fueled the process of technological change； and helped to shape a world in which the very survival of a nation would depend on its scientific and technical prowess. Flight is, and will continue to be, one of humankinds most significant accomplishments. This section features brief essays that describe significant events in aviation history, arranged chronologically on a timeline. Visitors to our Web site will be able to access hundreds of essays on aerospace topics； a rich collection of images； a timeline of significant aviation events； and a dictionary of persons, places, and things that are important to understanding the history of aviation and aerospace. 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 18頁(yè) 2.譯文 飛機(jī)的介紹 由于飛機(jī)的使命而使它有 許多的形狀和尺寸，但是所有的現(xiàn)代飛機(jī)有共同的特定成份。這些是機(jī)身，機(jī)翼 , 尾翼和舵面，起落架和動(dòng)力裝置 . 對(duì)于任何的飛機(jī)要飛起來(lái) , 它一定要能夠克服飛機(jī)自身的重量，及它的燃料，乘客 , 和貨物。機(jī)翼產(chǎn)生大部份的升力在空氣中支撐飛機(jī)。 為了產(chǎn)生升力，飛機(jī)與空氣有相對(duì)運(yùn)動(dòng)。 通常在位于機(jī)翼下方的引擎提供推力推動(dòng)飛機(jī)通過(guò)空氣。 機(jī)身是把飛機(jī)的所有塊以及其他一些大的部件結(jié)合在一起，它是飛機(jī)的身體。機(jī)身通常盡可能多被設(shè)計(jì) 成流線型減少阻力。 對(duì)于機(jī)身的設(shè)計(jì)變化多。機(jī)身包括駕駛員座艙那里飛行員和機(jī)組人坐的，而且它提供分布區(qū)給乘客和貨物。 它也可能攜帶各種不同種類的武器。 有些飛機(jī)在機(jī)身中攜帶燃料 ； 其它燃料則在機(jī)翼中。 除此之外，一個(gè)引擎可能也被安置在機(jī)身中。 機(jī)翼提供拖起飛機(jī)的重要升力。 升力從由重要的機(jī)翼的和空氣相對(duì)運(yùn)動(dòng)而被獲得。 機(jī)翼的代表性形狀同樣地從翼剖面看到的。機(jī)翼的平面形狀(如上方所看的翼形狀 )和它在機(jī)身上的布局 (包括影響它的角度 ) ，還有機(jī)身的形狀，在飛機(jī)的總體設(shè)計(jì)中考慮飛機(jī)的使命和必要的妥協(xié)處理是很必要的 . 操縱面（舵面）包括作為姿態(tài)，升起和阻力控制那些可動(dòng)翼面。 他們包括在后面的集群 , 飛機(jī)后面的結(jié)構(gòu)是用來(lái)控制和操縱飛機(jī)它連接在機(jī)翼的上面。 尾部通常有固定的水平線塊 (叫做水平的安定裝置 ) 和固定的垂直塊。 (被稱為垂直的安定裝置 )安定裝置提供安定給飛機(jī) -他們保持它飛的直線。 垂直的安定裝置使機(jī)頭不從邊到邊 (被稱為首搖 ) 搖擺而水平的安定裝置避免機(jī)頭 (被稱為縱搖 ) 的一個(gè)上上下下運(yùn)動(dòng)。 (在萊特兄弟第一架飛機(jī)南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 19頁(yè) 上，水平的安定裝置在機(jī)翼之前。 如此的一個(gè)結(jié)構(gòu)讓人驚奇。 它裝鉸鏈 , 在機(jī)翼的邊緣上部份叫做副翼 。它用來(lái)從一邊到另一邊轉(zhuǎn)動(dòng)翼。在飛機(jī)失速的時(shí)候拍打被裝鉸鏈或者轉(zhuǎn)動(dòng)副翼可以增加升力。主要在著路和起飛的時(shí)候用到。擾流板是為了要很快地在一個(gè)飛機(jī)翼上減少升力 ,來(lái)打亂在翼上氣流的裝置。 通過(guò)在每個(gè)翼上獨(dú)立地操作，他們可能提供一種橫滾控制替代形式。邊條翼的前面部份在起飛著路是產(chǎn)生另外的升力。在副翼表面和升降舵后面，方向舵是很小的移動(dòng)部件稱為調(diào)整片。它通過(guò)鉸鏈連接。他們的功能平衡飛機(jī)如果它頭重了 , 附于其后重的 , 或裝以翼重在穩(wěn)定的巡航情況下飛行 ； 在控制方面的壓力的飛行員的任何的設(shè)定飛行員希望維持升降舵，方向 舵和副翼 ； 而且?guī)椭苿?dòng)升降舵，方向舵和副翼來(lái)減輕飛行員移動(dòng)翼面的困難。 著陸裝置 或 起落架 ，是支撐飛機(jī)在 地面 停放 ,或在水中起飛和降落 。 該裝置可固定或收放 。大多數(shù)飛機(jī)的輪子被裝減震支柱上，減震支柱是用油氣填充到柱桶中。 特殊用途的起落裝置包括在雪地上可以滑行在水面上可以漂浮。為了能在航空母艦著陸，著陸阻攔鉤被應(yīng)用了。 向前運(yùn)動(dòng)或推進(jìn)是由一個(gè)產(chǎn)生推力的裝置也就是發(fā)動(dòng)機(jī)產(chǎn)生的。動(dòng)力裝置包括引擎和相關(guān)的配件。 主要的引擎類型是往復(fù)的 (或活塞類型 ), 和噴氣的 , 或噴氣式飛機(jī)引擎 , 像是沖壓式噴氣發(fā)動(dòng)機(jī)，脈膊式噴氣 發(fā)動(dòng)機(jī)，渦輪噴氣發(fā)動(dòng)機(jī)和火箭引擎。 螺旋槳把活塞式發(fā)動(dòng)機(jī)的旋轉(zhuǎn)曲軸的能量轉(zhuǎn)換成推力。 通常引擎被安裝在整流罩中鉸接在機(jī)翼下方 , 但是一些飛機(jī)如戰(zhàn)斗機(jī)被安裝在機(jī)身中。 其他結(jié)構(gòu)的那時(shí)也被使用過(guò)。舉例來(lái)說(shuō)，萊特兄弟的 1903年飛行者在飛機(jī)的前面有了推力螺旋槳 (螺旋槳在飛機(jī)的后面 ) ，升降舵在前面。 許多戰(zhàn)斗機(jī)也結(jié)合水平的安定裝置和升降舵變成一個(gè)裝置面。 有許多可能的飛機(jī)結(jié)構(gòu)，但是任何的結(jié)構(gòu)要提供飛行所需的動(dòng)力。 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 20頁(yè) 機(jī)翼 機(jī)翼是飛機(jī)被設(shè)計(jì)產(chǎn)生升力的 那些部份。機(jī)翼是主要的翼面 ，但是螺旋槳和尾翼或有時(shí)甚至機(jī)身本身也可能是翼面。翼面有一個(gè)前緣，一個(gè)后緣，一根弦和曲面。前緣是機(jī)翼的 前面 -首先碰到空氣的部分。 后緣是機(jī)翼的背面 -在那個(gè)地方氣流通過(guò)機(jī)翼的上表面和機(jī)翼下表面的氣流相碰。 機(jī)翼的要素 機(jī)翼的弦長(zhǎng)是機(jī)翼的前緣到后緣 的假想直線。它的曲面是她上下表面的曲線。這一條曲線以它離弦的多少來(lái)計(jì)算的。有時(shí)機(jī)翼有一點(diǎn)點(diǎn)弧度，看起來(lái)很平坦。 而有時(shí)它有很大的弧度 有很大的曲線。上弧是根據(jù)機(jī)翼的上表面的曲面。下弧是根據(jù)機(jī)翼的下表面的曲面。機(jī)翼的曲面影響它的升力。氣流流過(guò)機(jī)翼的方向相對(duì)于飛行軌跡被稱作為相對(duì)氣流。她方向總是和飛行軌跡相平行但相反。 起落架 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 21頁(yè) 起落架是在讓它安全地著陸的一個(gè)飛機(jī)的機(jī)身下面的結(jié)構(gòu)。 最早的起落架有滑橇構(gòu)成 , 但是設(shè)計(jì)者很快在它上面裝上了輪子。 起落架除 了吸收飛機(jī)的重量之外一定還要有吸收著陸的力量的一些機(jī)構(gòu)。早的起落架用柔性的材料作為起落架支柱。 (這個(gè)機(jī)構(gòu)連接機(jī)身和機(jī)輪 ) 當(dāng)著陸的時(shí)候，一些起落架使用一個(gè)吸震系統(tǒng)叫做減震支柱，有了這樣的減震器可使飛機(jī)平穩(wěn)著陸。 有許多形式的起落架：傳統(tǒng)的起落架有在飛機(jī)重心前面安裝兩個(gè)輪子再在尾部裝第三個(gè)小輪子。這個(gè)小的輪能在任何的方向轉(zhuǎn)。這一個(gè)結(jié)構(gòu)有綽號(hào) 尾拖 因?yàn)?, 當(dāng)飛機(jī)在地面上的時(shí)候，飛機(jī)的尾部比前部更接近地面。 前三點(diǎn)式起落架有一個(gè)前輪和在機(jī)身中部的一對(duì)后輪。 前輪利用方向舵腳蹬是可操縱的。 縱排的起落架 (也叫做自行車式起落架 ) 它是由兩個(gè)輪子組成的主起落架，旁邊還有兩個(gè)輔助輪組成。 起落架有固定的或可收縮的。 通常，比較小又比較便宜的飛機(jī)的起落架是固定的，在飛行時(shí)也是暴露在外的，因?yàn)樗闹圃旌途S護(hù)比較便宜。 可收縮的起落架能縮回機(jī)身之內(nèi)。 這一個(gè)特征使機(jī)構(gòu)避開(kāi)氣流而且減少了阻力。 在水上著陸的飛機(jī)配備有浮桶而不是輪子。 一些飛機(jī)有了可互換的浮桶和輪子，以便飛機(jī)即可在土地有可在水上著陸。 飛行過(guò)程中的四種載荷 飛行過(guò)程中的四種載荷是升力，阻力，推力和重力。 升力是機(jī)翼相對(duì)氣流的 運(yùn)動(dòng)而產(chǎn)生的力。 升力克服了飛機(jī)的重力。 它一定相等或大于對(duì)象的重力并該力的作用方向相反。升力可由增加飛機(jī)的向前速度或增加仰角而增加。 阻力是阻礙飛機(jī)向前運(yùn)動(dòng)的力。 它和推力相反由空氣的阻礙產(chǎn)生。 推力是由引擎和它的螺旋槳的作用產(chǎn)生的。 它通過(guò)推動(dòng)空氣向后運(yùn)動(dòng)南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 22頁(yè) 產(chǎn)生推動(dòng)飛機(jī)向前的力。 重力是由于飛機(jī)的自身的重量和它的負(fù)荷產(chǎn)生的，重力是向下的力。 它和升力相反。 當(dāng)推力和阻力是大小相等方向相反的時(shí)候，一架飛機(jī)處于平衡的狀態(tài)。 它將會(huì)作等速直線飛行。 如果推力或阻力變成比相反的力大 ,飛機(jī)失去它的平衡的狀態(tài)。 如果 推進(jìn)比累贅棒 ,飛機(jī)將會(huì)加速。 如果阻力比推力大 ,飛機(jī)將會(huì)失去速度最后下降。 飛行過(guò)程中的四種載荷 流線型化 流線型是物體個(gè)一個(gè)形狀 , 像是一個(gè)飛機(jī)機(jī)身或者機(jī)翼 ,通過(guò)這條空氣的流線來(lái)減小阻力或阻礙運(yùn)動(dòng)。曲線形狀讓空氣平滑地流過(guò)它。 平坦的形狀抵抗空氣流動(dòng)而且引起較多的阻力或抵抗。 流線型化減少大量抵抗力和增加升力。 為了產(chǎn)生比較小的抵抗力，物體的前面應(yīng)該做圓一點(diǎn)，而且身體應(yīng)該逐漸地從中央部分逐漸變小地往后彎。 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 23頁(yè) 流線型化減小了大量由機(jī)翼產(chǎn)生的阻力 迎角 迎角是飛機(jī)的縱軸和翼弦線之間的夾角。 迎角是按照一定的角度把機(jī)翼固定在機(jī)身上。 它是飛機(jī)的弦和飛機(jī)的縱軸形成的角度。飛機(jī)的這條縱軸是通過(guò)從飛機(jī)的前面到飛機(jī)的后面的機(jī)身想像的線。 通常，迎角是在機(jī)翼和飛機(jī)縱軸之角度。 飛機(jī)舵面 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 24頁(yè) 方向舵，升降舵和副翼在一架飛機(jī)上是主要的控制面。 方向舵控制飛機(jī)的首搖 ,升降舵控制它的縱搖 ,副翼控制它的滾動(dòng)。其它在下面被說(shuō)明。 襟翼是機(jī)翼可動(dòng)的部分，通常鉸接在每個(gè)機(jī)翼靠近機(jī)身的后緣。 飛行員擴(kuò)展而且縮回襟翼。 擴(kuò)展 襟翼增加翼弧形和翼的攻擊的角度。 這可以增加機(jī)翼的升力也可以增加阻力。襟翼使飛行員能夠作較險(xiǎn)竣的降落當(dāng)著陸時(shí)沒(méi)有增加的氣流速度。 他們也幫助飛機(jī)短距離起飛。 有許多不同類型的襟翼。一些鉸鏈?zhǔn)?，一些下滑?, 一些開(kāi)縫式 , 和即使在大的攻擊角度被試飛時(shí)也能使一些氣流平穩(wěn)流過(guò)機(jī)翼。 前緣縫翼是機(jī)翼前緣的凸起部分。 他們?cè)黾右淼纳?。前緣縫翼和襟翼一起運(yùn)作維持機(jī)翼上面的層流 (一個(gè)平滑的氣流 )。 擾流板減小升力。擾流板沿著翼的頂端的。 當(dāng)他們沒(méi)有在被用的時(shí)候 , 他們適宜的裝進(jìn)或埋在機(jī)翼的表面。 當(dāng)他們被用的時(shí)候 ，他們從翼的表面伸到氣流中破壞層流。擾流板的大小不同取決于要干擾多少的升力 ,不同的擾流板的設(shè)計(jì)是依照不同類型的飛機(jī)，但它們的功能是相同的。 有些裝置只減小阻力而不影響機(jī)翼的升力。 這些包括減速板 , 空氣動(dòng)力減速裝置，俯沖減速板或減速傘。 他們可能位于后緣或者可能從機(jī)身凸出。 這些裝置允許非常險(xiǎn)峻的降落和氣流速度的迅速改變。 飛行員能用縮回裝置即時(shí)停止他們的作用。 南昌航院 2006 屆畢業(yè)設(shè)計(jì) 飛機(jī)前起落架機(jī)構(gòu)設(shè)計(jì) 共 30 頁(yè) 第 25頁(yè) 一架飛機(jī)有旋轉(zhuǎn)的三個(gè)軸 : 垂直的 , 橫向的 , 和縱向的。 除了飛機(jī)向前運(yùn)動(dòng)外，飛機(jī)用三個(gè)力（升力，阻力和邊的力量）可以作繞三個(gè)軸的運(yùn)動(dòng)。這三根軸能被看成穿國(guó)飛機(jī)的三根桿，每根與另外二根相交。 交點(diǎn)就是飛機(jī)的重心。 每一個(gè)軸與另外二根又垂直。 經(jīng)過(guò)頭和尾部縱向擴(kuò)充的線叫做縱軸。 繞著這根軸旋轉(zhuǎn)叫做橫滾。 阻力是沿著這跟軸的力 , 但是在航線的相反方向。 從一邊翼尖到另一翼尖軸被稱為橫軸。 繞著這