時間：2011-03-11 23:11來源：藍(lán)天飛行翻譯 作者：admin 點(diǎn)擊：次
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centrifugal pump (fluid pump). A variable displacement pump which moves fluid by taking it into the center of a scroll-type impeller and slinging it outward by centrifugal action. Aircraft fuel boost pumps installed inside the fuel tanks are almost always centrifugal pumps. centrifugal switch. An electrical switch actuated by centrifugal force and mounted inside of a piece of rotating machinery. Centrifugal switches are used in capacitor-start induction motors to disconnect the start winding when the rotor reaches a specified speed. centrifugal tachometer. A type of mechanical tachometer used to measure the speed of rotation of a shaft or wheel. Two or three flyweights are mounted on a collar around a rotating shaft in such a way that, as they spin, centrifugal force pulls them away from the shaft. As they move away from the shaft, the collar moves up the shaft. As the collar moves up, it causes a pointer to move over a dial to indicate the speed being measured. centrifugal twisting force. See CTF. centrifugal twisting moment. See CTM. centrifuge (physical separator). A device used to separate a liquid mixture or suspension into its various components which have different specific gravities. A container of the liquid mixture is spun at a high speed, and the components having the higher specific gravities are slung to the outside where they are drawn off. centrifuge (space travel simulator). A large machine having a long motor-driven arm which moves a vehicle in a circular path at various rotational speeds. Humans and animals are carried in the vehicle to study the effect of prolonged acceleration, such as they would find while traveling in a spacecraft or rocket. centrifuging. A method of separating liquids which have different densities by spinning them in a centrifuge. centripetal force. The force within a body that opposes centrifugal force as the body rotates or spins. Centripetal force acts inside a piece of rotating machinery and tries to pull the rotating object in toward the center of its rotation. centroid. The center of mass of a body. It is the point about which all the mass can be considered to be concentrated. ceramic. Any of several hard, brittle, heat-resistant, noncorrosive materials made by shaping and then firing a mineral, such as clay, at a high temperature. Ceramic electrical insulators are stronger than glass, and they withstand high temperatures better than glass. ceramic magnet. A permanent magnet made by pressing together a mixture of ceramic material and sintered magnetic particles. Ceramic magnetic material is called ferromagnetic ceramic. CERAP (combined center-rapcon). An air traffic control facility which combines the function of an air route traffic control center (ARTCC) and a radar approach control facility. cerium. A lustrous, iron-gray, malleable, metallic, rare-earth chemical element. Cerium’s symbol is Ce, its atomic number is 58, and its atomic weight is 140.12. Cerium is used as a getter in the manufacture of electron tubes and as a constituent in friction-lighter flints. |
