Editing Jet engine (section)

{{Use Oxford spelling|date=September 2016}}
{{Short description|Aircraft engine that produces thrust by emitting a jet of gas}}
{{Infobox machine
| name              = Jet engine
| image             = F100 F-15 engine.JPG
| alt               =
| image_title       =
| image_link        =
| caption           = A [[Pratt & Whitney F100]] [[turbofan]] engine for the [[F-15 Eagle]]  being tested in the [[hush house]] at 
[[Florida Air National Guard]] base
| classification    = [[Internal combustion engine]]
| industry          = [[Aerospace industry|Aerospace]]
| application       = [[Aviation]]
| fuel_source       = [[Jet fuel]]
| components        = [[Compressor#Dynamic|Dynamic compressor]], [[Fan (machine)|Fan]], [[Combustor]], [[Turbine]], [[Propelling nozzle]]
| invented          = 1791, 1928, 1935
| inventor          = [[John Barber (engineer)|John Barber]], [[Frank Whittle]], [[Hans von Ohain]]
| examples          = 
}}
[[File:20140308-Jet engine airflow during take-off.jpg|thumb|Jet engine during take-off showing visible hot exhaust ([[Germanwings]] [[Airbus A319]])]]
<!--When editing intro please try to keep it general -->

A '''jet engine''' is a type of [[reaction engine]], discharging a fast-moving [[jet (fluid)|jet]] of heated gas (usually air) that generates [[thrust]] by [[jet propulsion]]. While this broad definition may include [[Rocket engine|rocket]], [[Pump-jet|water jet]], and hybrid propulsion, the term {{Em|jet engine}} typically refers to an internal combustion [[airbreathing jet engine|air-breathing jet engine]] such as a [[turbojet]], [[turbofan]], [[ramjet]], [[pulse jet engine|pulse jet]], or [[scramjet]]. In general, jet engines are [[internal combustion engine]]s.

Air-breathing jet engines typically feature a [[Axial compressor|rotating air compressor]] powered by a [[turbine]], with the leftover power providing thrust through the [[propelling nozzle]]—this process is known as the [[Brayton cycle|Brayton thermodynamic cycle]]. [[Jet aircraft]] use such engines for long-distance travel. Early jet aircraft used turbojet engines that were relatively inefficient for subsonic flight. Most modern subsonic jet aircraft use more complex [[High-bypass turbofan|high-bypass turbofan engines]].  They give higher speed and greater [[fuel efficiency]] than piston and propeller [[aeroengine]]s over long distances. A few air-breathing engines made for high-speed applications (ramjets and [[scramjet]]s) use the [[dynamic pressure|ram effect]] of the vehicle's speed instead of a mechanical compressor.

The thrust of a typical [[jetliner]] engine went from {{cvt|5000|lbf|kN}} ([[de Havilland Ghost]] turbojet) in the 1950s to {{cvt|115,000 |lbf|kN}} ([[General Electric GE90]] turbofan) in the 1990s, and their reliability went from 40 in-flight shutdowns per 100,000 engine flight hours to less than 1 per 100,000 in the late 1990s. This, combined with greatly decreased fuel consumption, permitted routine [[ETOPS|transatlantic flight by twin-engined airliners]] by the turn of the century, where previously a similar journey would have required multiple fuel stops.<ref>{{cite web|url=http://www.airbus.com/fileadmin/media_gallery/files/safety_library_items/AirbusSafetyLib_-FLT_OPS-SUPP_TECH-SEQ07.pdf |title=Flight Operations Briefing Notes – Supplementary Techniques : Handling Engine Malfunctions |publisher=Airbus |url-status=dead |archive-url=https://web.archive.org/web/20161022181226/http://www.airbus.com/fileadmin/media_gallery/files/safety_library_items/AirbusSafetyLib_-FLT_OPS-SUPP_TECH-SEQ07.pdf |archive-date=2016-10-22 }}</ref>