时间：2011-03-11 23:18来源：蓝天飞行翻译 作者：航空 点击：次
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vapor degreasing. A method of removing grease and oil from a metal part by spraying it with hot vapors of a solvent such as trichlorethylene. vaporization. The act of changing of a liquid into a vapor. vapor lock (reciprocating engine malfunction). A condition of fuel starvation that can occur in a reciprocating engine fuel system. If the fuel in the line between the tank and the carburetor is heated enough to cause it to vaporize, a bubble of fuel vapor will form in the line. If the vapor pressure of this bubble is high enough, it will block the fuel and prevent it from flowing to the engine. This is a vapor lock. vapor pressure. The pressure of the vapor above a liquid needed to prevent the liquid evaporating, or changing into a vapor. When an aircraft ascends to an altitude at which the air pressure is lower than the vapor pressure of the fuel, vapor leaves the fuel. The fuel “boils.” Vapor pressure is measured in pounds per square inch at a specified temperature. vapor trail. A long trail of visible moisture left by an airplane as it flies at high altitude through very cold air. Vapor trails are caused by the condensation of water vapor in the exhaust gases leaving the engines. Vapor trails look like long, thin clouds, and they are often called contrails (condensation trails). vapour. The British spelling of vapor. VAPC (variable absolute pressure controller). A type of turbocharger controller that uses a cam actuated by the engine throttle to maintain a constant upper-deck pressure for each position of the throttle valve. A VAPC differs from an absolute pressure controller (APC) which maintains a constant upper-deck pressure only for full-throttle operation. The bellows in the VAPC controls the position of the valve, but the throttle controls the position of the valve seat. variable-angle stator vanes (gas turbine engine component). Compressor stator vanes whose angle is controlled by fuel pressure from the fuel control unit. By varying the stator-vane angle, the air directed into the first stages of the compressor meets the rotor blades at an angle that minimizes the possibility of compressor stall. variable capacitor (electrical component). A capacitor whose capacity can be changed. The capacity of a variable capacitor can be changed by varying the area of the plates, the distance between the plates, or the dielectric between the plates. variable-displacement fluid pump. A type of fluid pump whose output can be changed to suit the demands placed on it. A centrifugal pump moves an amount of fluid determined by the opposition at its discharge port. The less opposition there is, the greater the amount of fluid the pump moves. |
