时间：2011-03-11 23:11来源：蓝天飞行翻译 作者：admin 点击：次
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Centrifugal boost pumps have a small agitator propeller on top of the pump impeller. This agitator causes the vapors in the fuel to be released before the fuel leaves the tank. boost venturi. A small, auxiliary venturi whose discharge is located in the throat of a larger venturi. Boost venturis increase the pressure drop produced by the main venturi. They are installed in such devices as carburetors and in the large venturi tubes used to provide the low pressure for some vacuum-operated flight instruments. boosted brake (aircraft hydraulic brake). A form of power brake which uses hydraulic system pressure to help the pilot apply force to the brake master cylinder. When the brake pedal is depressed, hydraulic system pressure acts on the piston in the brake master cylinder to apply the brakes. Boosted brakes and power brakes are not the same. Power brake systems use hydraulic system pressure in the brake wheel cylinders themselves. boosted control system (aircraft flight controls). Flight controls of large, high-performance aircraft actuated by hydraulic cylinders. Hydraulic fluid under pressure is directed into the cylinders by valves actuated by the cockpit flight controls. booster coil (ignition system component). An induction coil excited by pulsating DC supplied by the aircraft battery and a vibrator. Booster coils produce a high voltage, which is directed to an auxiliary trailing finger on the rotor of the magneto distributor. When this high voltage jumps to ground across the electrodes of the spark plug, it produces a hot and late spark for starting the engine. booster magneto. A small, auxiliary, hand-cranked magneto used with some of the older aircraft engines to provide a hot, retarded spark for starting the engine. bootstrapping. A self-initiating or self-sustaining action. In a turbocharger system, bootstrapping describes a transient increase in engine power that causes the turbocharger to speed up, which in turn causes the engine to produce more power. The word bootstrap comes from the figure of speech “a person lifts himself by his own bootstraps.” bore (dimension). The diameter of a round hole. The distance across the hole at its widest point. bore (engine dimension). The diameter of the inside of the cylinder of a reciprocating engine. borescope (inspection instrument). An instrument used to examine the inside of a structure through a very small hole. The inside of a turbine engine and the inside of the cylinder of a reciprocating engine, for example, can be examined by inserting the probe of the borescope through a small inspection hole or through a spark plug hole. A borescope furnishes its own light, and some borescopes have different ranges of magnification. Some borescopes are fitted to a camera to photograph the inside of the structure. A modern trend in borescopes is to place a video pickup on the borescope tube and display the results on a small television screen. boric acid. A white crystal (H3BO3) that can be dissolved in water to make a weak acid solution. A boric acid solution can be used to neutralize spilled electrolyte from nickel-cadmium batteries. |
