INTERNAL COMBUSTION ENGINE
The internal combustion engine is an engine in which the combustion of a fuel (normally a fossil fuel) occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine (ICE) the expansion of the high-temperature and high-pressure gases produced by combustion apply direct force to some component of the engine. The force is applied typically to pistons, turbine blades, or a nozzle. This force moves the component over a distance, transforming chemical energy into useful mechanical energy. The first commercially successful internal combustion engine was created by Étienne Lenoir. ...view middle of the document...
Generally using fossil fuel(mainly petroleum), these engines have appeared in transport in almost all vehicles (automobiles, trucks, motorcycles, boats, and in a wide variety ofaircraft and locomotives).
Where very high power-to-weight ratios are required, internal combustion engines appear in the form of gas turbines. These applications include jet aircraft, helicopters, large ships and electric generators.
TYPES OF INTERNAL COMBUSTION ENGINE
Engines can be classified in many different ways: By the engine cycle used, the layout of the engine, source of energy, the use of the engine, or by the cooling system employed.
Internal combustion engines can be classified by their configuration.
Common layouts of engines are:
* Two-stroke engine
* Four-stroke engine (Otto cycle)
* Six-stroke engine
* Diesel engine
* Atkinson cycle
* Miller cycle
* Wankel engine
* Gas turbine
* Jet engine (including turbojet, turbofan, ramjet, Rocket, etc.)
As their name implies, four-stroke internal combustion engines have four basic steps that repeat with every two revolutions of the engine:
1. Intake stroke: The first stroke of the internal combustion engine is also known as the suction stroke because the piston moves to the maximum volume position (downward direction in the cylinder) creating a drop in pressure. The inlet valve opens as a result of the cam lobe pressing down on the valve stem, and the vaporized fuel mixture is sucked into the combustion chamber. The inlet valve closes at the end of this stroke.
2. Compression stroke: In this stroke, both valves are closed and the piston starts its movement to the minimum volume position (upward direction in the cylinder) and compresses the fuel mixture. During the compression process, pressure, temperature and the density of the fuel mixture increases.
3. Power stroke: When the piston reaches a point just before top dead center, the spark plug ignites the fuel mixture. The point at which the fuel ignites varies by engine; typically it is about 10 degrees before top dead center. This expansion of gases caused by ignition of the fuel produces the power that is transmitted to the crank shaft mechanism.
4. Exhaust stroke: In the end of the power stroke, the exhaust valve opens. During this stroke, the piston starts its movement in the maximum volume position. The open exhaust valve allows the exhaust gases to escape the cylinder. At the end of this stroke, the exhaust valve closes, the inlet valve opens, and the sequence repeats in the next cycle. Four-stroke engines require two revolutions.
Many engines overlap these steps in time; turbine engines do all steps simultaneously at different parts of the engines.
All internal combustion engines depend on combustion of a chemical fuel, typically with oxygen from the air (though it is possible to inject nitrous oxide to do more of the same thing and...