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From the geometry shown in the diagram above, the following variables are defined: rod length (distance between piston pin and crank pin) crank radius (distance between crank center and crank pin, i.e. half stroke)
The Diesel cycle is a combustion process of a reciprocating internal combustion engine. In it, fuel is ignited by heat generated during the compression of air in the combustion chamber, into which fuel is then injected. This is in contrast to igniting the fuel-air mixture with a spark plug as in the Otto cycle (four-stroke/petrol) engine.
In piston engines, static compression ratio is determined using the cylinder volume when the piston is at the top and bottom of its travel. The compression ratio is the ratio between the maximum and minimum volume during the compression stage of the power cycle in a piston or Wankel engine .
The first person to build a working four-stroke engine, a stationary engine using a coal gas-air mixture for fuel (a gas engine), was German engineer Nicolaus Otto. [4] This is why the four-stroke principle today is commonly known as the Otto cycle and four-stroke engines using spark plugs often are called Otto engines.
IMEP may be determined by planimetering the area in an engine's pV-diagram. Since naturally aspirated four-stroke engines must perform pumping work to suck the charge into the cylinder, and to remove the exhaust from the cylinder, IMEP may be split into the high-pressure, gross mean effective pressure (GMEP, p m g {\displaystyle p_{mg}} ) and ...
Free-piston engine used as a gas generator to drive a turbine. A free-piston engine is a linear, 'crankless' internal combustion engine, in which the piston motion is not controlled by a crankshaft but determined by the interaction of forces from the combustion chamber gases, a rebound device (e.g., a piston in a closed cylinder) and a load device (e.g. a gas compressor or a linear alternator).
Engines using the Diesel cycle are usually more efficient, although the Diesel cycle itself is less efficient at equal compression ratios. Since diesel engines use much higher compression ratios (the heat of compression is used to ignite the slow-burning diesel fuel), that higher ratio more than compensates for air pumping losses within the engine.
Engine displacement is the measure of the cylinder volume swept by all of the pistons of a piston engine, excluding the combustion chambers. [1] It is commonly used as an expression of an engine's size, and by extension as an indicator of the power (through mean effective pressure and rotational speed ) an engine might be capable of producing ...