飛機發動機術語英文解釋（A-B）
 

Acceleration lag --  in the turbine engine, delay between the time instant power is requested and when power is available. The time it takes the engine to accelerate and give the required power increase.   Aerodynamic drag --  force which thrust must overcome to move an aircraft forward. Design can lesson aerodynamic drag through streamlining. Drag increases with increased speed.   Airbleed actuator --  device that operates the interstage bleed system, to improve compressor acceleration characteristics by unloading small amounts of compressed air.   Air density--  total mass of air per given volume, the weight of a given volume of air. Air is denser at lower altitude, at lower temperature, and lower humidity.   Airfoil profile --  outline of an airfoil section.   Airfoil section --  cross section of an airfoil parallel to a specific reference plane.   Air-fuel ratio --  Ideal mixture of 15 parts of air to 1 part of fuel by weight; the mixture to be burned in the combustion chamber.   Air inlet --  large, smooth aluminum or magnesium duct at mouth of engine which conducts air into the compressor with minimum turbulence and restriction.   Aluminum alloy --  any of a variety of alloys formed by combining commercially pure aluminum with other metals or materials such as copper, silicon, manganese, magnesium, and zinc. These alloying agents maybe added singly or in combination to produce a metal with desired characteristics or strength, heat resistance, corrosion resistance, and the like. Both wrought-and cast-aluminum alloys are widely used in the manufacture of rotor blades and aircraft propellers. 
 

 Ambient --  condition of atmosphere existing around the engine, such as ambient pressure or temperature.   Annular combustion chamber --  two-part combustion chamber made up of an annular liner and a housing assembly. The compressed air goes into a ring-shaped space formed by the annular liner around the turbine shaft rather than into individual combustion chambers. The space between the outer liner wall and the housing assembly allows the flow of cooling air. Used with axial-flow and dual compressors.   Annular reverse-flow engine --  type of gas turbine engine most commonly used in Army aircraft. Airflow direction is reversed in the combustion area.   Anti-icing system --  device that supplies hot air under pressure to prevent icing of the inlet housing areas and inlet guide vanes. Hot scavenged oil is also circulated through internal passages in the walls and struts.   Army Spectrometric Oil Analysis Program (ASOAP) --  periodic oil analysis for microscopic metal particles. This takes place at an oil analysis laboratory.   Atmospheric pressure --  barometric pressure exerted by the atmosphere as a result of gravitational attraction above the point in question.   Atomizer --  nozzle that creates minute particles and accurately shaped spray of fuel suitable for rapid mixing and combustion.   Axial-flow compressor --  one in which the air is compressed parallel to the axis of the engine. It is made up of a series of alternating rotor and stator vane stages.   Bending --  combination of tension and compression. The inside curve is under compression; the outside is under tension.   Bleed system --  device that unloads small amounts of air to relieve pressure.