時間：2011-03-11 23:11來源：藍(lán)天飛行翻譯 作者：admin 點擊：次
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aerodynamic lift. A force produced by air moving over a specially shaped surface called an airfoil. Lift acts in a direction perpendicular to the direction the air is moving. Airplane wings and helicopter rotors produce vertical lift, and propellers produce aerodynamic lift (thrust) in a horizontal plane. The amount of aerodynamic lift is determined by the density of the air, the speed of the air, and the direction the air is flowing as it approaches the airfoil. L = (CL σ V2 S) / 295 L = Lift (pounds) CL = Coefficient of lift (dimensionless) σ = Air density ratio (dimensionless) V2 = Square of airstream velocity (knots) S = Airfoil planform area (square feet) 295 = A constant used when velocity is given in knots aerodynamics. The branch of science that deals with the forces produced by air flowing over specially shaped surfaces called airfoils. Wings and helicopter rotors produce a vertical aerodynamic force, and propellers produce a horizontal force. Aerodynamic forces inside a turbojet engine produce pressure and velocity changes in the air as it passes through the compressor and turbine. aerodynamic shape. The shape of an object with reference to the airflow over it. Certain shapes cause an air pressure difference across the surface which produces lift. Other shapes are designed in such a way that they produce the minimum amount of drag. aerodynamic twisting force. See ATF. aeroelastic tailoring. The design of an aerodynamic surface whose strength and stiffness are matched to the aerodynamic loads imposed upon it. Aerofiche. The registered trade name for a form of microfiche used in the aircraft industry. Two hundred and eighty-eight frames of information can be placed on a single four-by-six card of film called a fiche. Aeromatic propeller. A patented propeller that has counterweights around the blade shanks and the blades angled back from the hub to increase the effects of aerodynamic and centrifugal twisting forces. This propeller automatically maintains a relatively constant RPM for any throttle setting. aeronautical beacon. A visual navigational aid displaying flashes of white and/or colored light. These flashes indicate the location of an airport, a heliport, a landmark, a certain point of a Federal airway in mountainous terrain, or an obstruction. The colors and meaning of the more commonly used beacons are: Color Meaning white and green ---------------------------------------lighted land airport green----------------------------------------------------lighted land airport white----------------------------------------------------unlighted land airport white and yellow--------------------------------------lighted water airport yellow --------------------------------------------------lighted water airport green, yellow and white------------------------------lighted heliport |
