Internal combustion engine

An internal combustion engine (ICE or IC engine) is a <a href="/facts/Heat_engine/t1gq4r5d">heat engine</a> in which the <a href="/facts/Combustion/ohQoWj8z">combustion</a> of a <a href="/facts/Fuel/H8DIRL1j">fuel</a> occurs with an <a href="/facts/Oxidizer/1FQzB8pQ">oxidizer</a> (usually air) in a <a href="/facts/Combustion_chamber/FNqjDrN8">combustion chamber</a> that is an integral part of the <a href="/facts/Working_fluid/GvHk1AMq">working fluid</a> flow circuit. In an internal combustion engine, the expansion of the high-<a href="/facts/Temperature/QyGe4gmj">temperature</a> and high-<a href="/facts/Pressure/eyc37GRG">pressure</a> gases produced by combustion applies direct <a href="/facts/Force/LNAUWMwK">force</a> to some component of the engine. The force is typically applied to <a href="/facts/Piston/z7pN46u7">pistons</a> (<a href="/facts/Reciprocating_engine/ItLAxmW3">piston engine</a>), <a href="/facts/Turbine_blade/yY8jFPgl">turbine blades</a> (<a href="/facts/Gas_turbine/JJJNwXrG">gas turbine</a>), a <a href="/facts/Wankel_engine/IstzAyor">rotor (Wankel engine)</a>, or a <a href="/facts/Propulsive_nozzle/GDstAvRx">nozzle</a> (<a href="/facts/Jet_engine/CJjFpeqt">jet engine</a>). This force moves the component over a distance. This process transforms <a href="/facts/Chemical_energy/Y3VP3Ifq">chemical energy</a> into <a href="/facts/Kinetic_energy/aJRxUd4p">kinetic energy</a> which is used to propel, move or power whatever the engine is attached to.
The first commercially successful internal combustion engines were invented in the mid-19th century. The first modern internal combustion engine, the <a href="/facts/Otto_engine/Nc8z6Xv9">Otto engine</a>, was designed in 1876 by the German engineer <a href="/facts/Nicolaus_Otto/CtBoqHsx">Nicolaus Otto</a>. The term internal combustion engine usually refers to an engine in which combustion is <a href="/facts/Intermittency/CEIrNsP0">intermittent</a>, such as the more familiar <a href="/facts/Two-stroke/Al4uUeo9">two-stroke</a> and <a href="/facts/Four-stroke/70vDIDvJ">four-stroke</a> piston engines, along with variants, such as the <a href="/facts/Six-stroke_engine/I8gHYNhT">six-stroke</a> piston engine and the <a href="/facts/Wankel_engine/IstzAyor">Wankel rotary engine</a>. A second class of internal combustion engines use continuous combustion: <a href="/facts/Gas_turbine/JJJNwXrG">gas turbines</a>, <a href="/facts/Jet_engine/CJjFpeqt">jet engines</a> and most <a href="/facts/Rocket_engine/XT5gaFAb">rocket engines</a>, each of which are internal combustion engines on the same principle as previously described. In contrast, in <a href="/facts/External_combustion_engine/o1uQ9SnS">external combustion engines</a>, such as <a href="/facts/Steam_engine/f7hN8vzm">steam</a> or <a href="/facts/Stirling_engine/mvvKyMGI">Stirling engines</a>, energy is delivered to a working fluid not consisting of, mixed with, or contaminated by combustion products. Working fluids for external combustion engines include air, hot water, <a href="/facts/Pressurized_water_reactor/2hSL4Hv0">pressurized water</a> or even <a href="/facts/Boiler/uPqTq0I6">boiler</a>-heated <a href="/facts/Sodium-cooled_fast_reactor/4F7zMYRJ">liquid sodium</a>.
While there are many stationary applications, most ICEs are used in mobile applications and are the primary power supply for <a href="/facts/Vehicle/jSIEqANL">vehicles</a> such as <a href="/facts/Cars/I1IsH8IK">cars</a>, <a href="/facts/Aircraft/EhC4mBep">aircraft</a> and <a href="/facts/Boats/dz9LnNN6">boats</a>. ICEs are typically powered by <a href="/facts/Hydrocarbon/Dcg95Ju5">hydrocarbon</a>-based fuels like <a href="/facts/Natural_gas/9MYQ7NAP">natural gas</a>, <a href="/facts/Gasoline/lcnxq5BS">gasoline</a>, <a href="/facts/Diesel_fuel/lm71xc19">diesel fuel</a>, or <a href="/facts/Ethanol/3lCLfBSP">ethanol</a>. <a href="/facts/Renewable_fuels/flb46VjG">Renewable fuels</a> like <a href="/facts/Biodiesel/M6FkfJXH">biodiesel</a> are used in compression ignition (CI) engines and <a href="/facts/Ethanol_fuel/E1m7CDM4">bioethanol</a> or <a href="/facts/ETBE/eocybh5g">ETBE</a> (ethyl tert-butyl ether) produced from bioethanol in spark ignition (SI) engines. As early as 1900 the inventor of the diesel engine, <a href="/facts/Rudolf_Diesel/N9LXK47e">Rudolf Diesel</a>, was using peanut oil to run his engines. Renewable fuels are commonly blended with fossil fuels. <a href="/facts/Hydrogen/BoYHjl0J">Hydrogen</a>, which is rarely used, can be obtained from either fossil fuels or renewable energy.

Internal combustion engine open-in-new

Internal combustion engine