完整word版航空发动机术语.docx

1、完整word版航空发动机术语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. Des

2、ign 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 v

3、olume, 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

4、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

5、 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 wrough

6、t-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 hou

7、sing 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 compress

8、ors. 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 oi

9、l 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 r

10、esult 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

11、 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. Boss - raised rim around a hole; e.g., axle hole

12、in a wheel. Circular projection on a casting, usually serving as the seat for a bolt head or nut. Brayton cycle - constant pressure cycle, with four basic operations which it accomplishes simultaneously and continuously for an uninterrupted flow of power. The turbine engine operates on this cycle.Ca

13、mber - the curvature of an airfoils surfaces from the chord line. It maybe positive, negative, or zero. Can-annular combustion chamber - one with characteristics of both the annular types. It has an outer shell and a number of individual cylindrical liners. Can combustion chamber - one made up of in

14、dividual combustion chambers in which the air from the compressor enters each individual chamber through the adapter. Center of pressure - aerodynamic center of an airfoil; the point where all forces act. Centrifugal axial-flow compressor - combination of the centrifugal-flow and the axial-flow comp

15、ressor. It usually consists of a five-or seven-stage axial-flow compressor and one centrifugal-flow compressor. Also called the dual compressor. Centrifugal-flow compressor - one with an impeller (rotor), stator, and compressor manifold. The rotor revolves at high speed drawing air into the blades.

16、Centrifugal force accelerates the air, and it moves through the stator and through the manifold. Centrifugal twisting movement - force that tends to streamline rotating blades with the plane of rotation. Choked nozzle - a nozzle whose flow rate has reached the speed of sound. Chord line - imaginary

17、line drawn between the leading and trailing edges of an airfoil. Combustion - process of burning the fuel-air mixture in a gas turbine engine. Combustion chamber - part of a turbine engine in which the propulsive power is developed by combustion of the injected fuel and the expansive force of the re

18、sulting gases. Combustion chamber liner - engine part usually constructed of welded high-nickel steel, subjected to flame of extremely high temperature. It is behind the compressor and receives the compressed air which is mixed with fuel and ignited. The combustor is where the combustion takes place

19、. Compressibility effects - the phenomenon encountered at extremely high speeds (near the speed of sound) when air ceases to flow smoothly over the wings (or blade) and piles up against the leading edge, causing extreme buffeting and other effects. Compressor - that section of an engine that produce

20、s an increase in air pressure. It is made up of rotating and stationary vane assemblies. It is the gas producer, or it may be thought of as an air pump. Compressor rotor - impeller, may be thought of as an air pump. It accelerates the air rearward into the first stage vane assemblies. Compressor sta

21、ll - separation of the airflow from the suction surface of the freed or rotating blades of a compressor. Any degree of stall reduces airflow. Concave - pressure side of an airfoil. Conduction - transfer of heat through material by communication of kinetic energy from particle to particle rather than

22、 by a flow of heated material. Convergent area - place where the cross-sectional area of a duct becomes smaller. Convergent exhaust duct - duct used on fixed-wing aircraft; formed by tapering toward the rear of the duct. Convex - suction side of an airfoil. Crossover tube - duct carrying flame to th

23、e individual cylindrical liners of the can-annular combustion chamber.Diffuser - aft structural member of an engine. It receives high velocity air from the centrifugal impeller and decreases velocity and increases air pressure. In the combustor, a diffuser forms a divergent flow path for the exhaust

24、 gases. Diffusion - process by which gases intermingle as the result of their spontaneous movement caused by thermal agitation. Directional references - specific definitions of terms referring to gas turbine engines to identify front and rear, right and left, bottom and top. Divergent area - place w

25、here air flows from a smaller into a larger area. Divergent exhaust duct - used on helicopter. Device to diffuse the exhaust gases rearward and to eliminate thrust. Drag parasite - drag caused by any member or structure which does not contribute to lift, such as engine cowlings. Drag profile - frict

26、ion resistance produced by a member moving through the air; in simple terms, the stickness of air against the surface of an airfoil. Dry-cleaning solvent - cleaning compound that maybe used for all metal parts. Dry-sump engine - one in which the oil is stored separate from the engine. Dual compresso

27、r - see centrifugal-flow, axial-flow compressor. Duplex nozzle - dual-orifice channel through which highly atomized and accurately shaped sprays of fuel go into the combustion chamber. Dynamic load - load on an aircraft due to a dynamic force.Effective angle of attack - that part of a given angle of

28、 attack that lies between the chord of an airfoil and a line representing the resultant velocity of the disturber airflow. End play - longitudinal back-and-forth play of a shaft. Engine airflow path - route of the airflow through the engine. Engine oil pressure indicating system - device that gives

29、continuous readings of engine oil pump pressure in psi. Engine oil temperature indicating system - device electrically connected to the 28 VDC system which transmits temperature readings to the indicator in degrees centigrade. Engine speed notation - the capital letter N, which represents the rotati

30、onal speed of the engine. When a number is placed after the N (as in N1), it indicates a specific system on the engine. Engine stations - specific locations on the engine designating temperature or pressure-measuring locations. For example, T3 means the third temperature pickup on the engine. Engine

31、 surge - result of compressor stall. The complete engine in stall. Exhaust - hot gases discharged from the engine through the exhaust diffuser section. Exhaust diffuser - section composed of an inner and outer housing, separated by hollow struts across the exhaust passage. It forms a divergent flow path for the exhaust gases. Exhaust gas temperature indicator - sensitive millivoltmeter calibrated in degree centigrade, activated by an electrical force generated by its thermocouple.Feedback - relay through the controls of aerodynamic