- 行业: Aviation
- Number of terms: 16387
- Number of blossaries: 0
- Company Profile:
Aviation Supplies & Academics, Inc. (ASA) develops and markets aviation supplies, software, and books for pilots, flight instructors, flight engineers, airline professionals, air traffic controllers, flight attendants, aviation technicians and enthusiasts. Established in 1947, ASA also provides ...
A form of precision resistance-measuring instrument which is a modification of the Wheatstone bridge. A Kelvin bridge minimizes the effect of lead and contact resistance and is used for accurate measurements of low resistances.
Industry:Aviation
A form of radio interference caused by rain, snow, or dust particles hitting the antenna and inducing a small radio-frequency voltage into it.
Industry:Aviation
A form of reaction engine that produces forward thrust by the rearward ejection of a stream of ionized particles. Ion engines using ionized particles produced by nuclear reaction have been proposed for space flight.
Industry:Aviation
A form of reaction engine whose fuel and oxidizer contain all of the oxygen needed for the release of heat energy. The released heat expands the gases which are ejected at a high velocity from a nozzle at the rear of the rocket. Rocket engines can operate in outer space where there is no atmosphere.
Industry:Aviation
A form of reciprocating engine in which the cylinders are arranged in two banks, separated by an angle of between 45° and 90°. Pistons in two cylinders, one in each bank, are connected to each of the crankshaft throws.
Industry:Aviation
A form of reciprocating engine in which the fuel-air mixture inside the cylinder is ignited by an electric spark. The spark is timed to occur when the piston is in the correct position on the compression stroke.
Industry:Aviation
A form of reciprocating engine that was at one time very popular for use on aircraft. The cylinders are arranged radially around a small central crankcase. Radial engines have an exceptionally good power-to-weight ratio, but they have so much frontal area that they cause an excessive amount of aerodynamic drag and are not efficient for modern high-speed airplanes.
Industry:Aviation
A form of reciprocating engine used in some early airplanes because of its light weight. In a rotary radial engine, the crankshaft is attached to the airframe and the crankcase, cylinders, and propeller rotate. Rotary radial engines were popular up through World War I.
Industry:Aviation
A form of reciprocating engine which has an intake and an exhaust valve in each cylinder. Four strokes of the piston (two in and two out) are needed to change chemical energy in the fuel into mechanical energy at the rotating crankshaft.
During the intake stroke, the piston moves inward, with the intake valve open and the exhaust valve closed. A mixture of fuel and air is pulled into the cylinder through the carburetor.
On the compression stroke, the piston moves outward with both valves closed. This compresses the fuel-air mixture. Near the end of the compression stroke, the spark plug fires and ignites the compressed fuel-air mixture.
The burning fuel heats and expands the air inside the cylinder, and the expanding air forces the piston inward on the power stroke. Near the end of the power stroke, the exhaust valve opens.
During the exhaust stroke, the piston moves outward with the exhaust valve open. As the piston moves outward, it forces the burned gases from the cylinder, and the cylinder is prepared for another cycle of operation.
Industry:Aviation
A form of reciprocating engine which uses heat produced by compressing the air in the cylinder to ignite the fuel.
A diesel engine is a compression-ignition engine. The piston, moving upward in the cylinder, compresses and heats the air. When the piston is near the top of its stroke, fuel is sprayed into the hot air, and it ignites and burns.
Industry:Aviation
