Jet engine Definition and 7 Discussions

A jet engine is a type of reaction engine discharging a fast-moving jet that generates thrust by jet propulsion. While this broad definition can include rocket, water jet, and hybrid propulsion, the term jet engine typically refers to an internal combustion airbreathing jet engine such as a turbojet, turbofan, ramjet, or pulse jet. In general, jet engines are internal combustion engines.
Airbreathing jet engines typically feature a rotating air compressor powered by a turbine, with the leftover power providing thrust through the propelling nozzle—this process is known as the 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 engines. They give higher speed and greater fuel efficiency than piston and propeller aeroengines over long distances. A few air-breathing engines made for high speed applications (ramjets and scramjets) use the ram effect of the vehicle's speed instead of a mechanical compressor.
The thrust of a typical jetliner engine went from 5,000 lbf (22,000 N) (de Havilland Ghost turbojet) in the 1950s to 115,000 lbf (510,000 N) (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 transatlantic flight by twin-engined airliners by the turn of the century, where previously a similar journey would have required multiple fuel stops.

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  1. VTOL147

    VTOL Jet Engine Aircraft and VTOL Jet Engine

    I am thinking about VTOL jet engine aircrafts like the following example (an ambulance). To be able to buid that kind of aircraft VTOL jet engines are needed. At the moment there are no VTOL jet engines available, but I have my own proposal: I have questions to jet engine experts. Is my...
  2. E

    B Warp jet?

    I was looking at videos on how a warp drive theoretically could work: by compressing space in front and expanding space in the back. This reminded me of a jet engine compressing air and blasting it out of a nozzle. My question is, could you build a sort of warp jet that would compress space...
  3. A

    Could you create thrust with water vapor?

    Whilst I was thinking of hydrogen combustion jet engines. I thought of a little idea... What if you could create thrust with water vapor the same way you could with the exhaust gas of a jet engine. (NOTE: I have no experience in engineering and I only have a mild interest in it). If this is...
  4. BoeingJet

    Railgun-Powered Ramjet Design

    Recently, I designed (in my head) a Hypervelocity Passenger Vehicle (just a cool name for really high speed transports). I immediately ran into engine design problems ( I like designing everything stand-alone), since regular jet engines can't get to Mach 8.8 without burning up into flames, and...
  5. A

    Why do Jet fighter pilots experience a greater G-force?

    Hi! I'm a high school student, aspiring to pursue a career in Astronautical Engineering. I always try and ponder on questions about everyday aerodynamics and physics. So, here's a question from you from an aspiring scholar. It is known that, at high velocities, pilots in super-sonic jet...
  6. G

    Practical measurements of ramjet engine

    Hello everyone I am trying to design a ramjet engine. For that I need measurements of its parts. Does anyone know how to calculate them or have a link to a website where I could find more information?
  7. Y

    Jet engine position

    Hello. Do you think the idea of placing the jet engine at the front is plausible? Why? Why not? Thanks Yrjosmiel