09-10-2017, 01:26 PM
A jet engine is a jet engine that delivers a rapid jet that generates thrust by jet propulsion. This broad definition includes air jet engines (turbojets, turbojets, jet jets, and jet jets) and non-breathing air jet engines (such as rocket engines). In general, jet engines are combustion engines.
In common parlance, the term "jet engine" refers to an internal combustion air jet engine. These typically feature a rotary air compressor driven by a turbine, with the surplus energy providing the thrust via a propellant nozzle - this process is known as Brayton thermodynamic cycle. Jet airplanes use these engines for long distance travel. Early jet aircraft used turbojet engines that were relatively ineffective for subsonic flight. Modern subsonic aircraft usually use more complex high-bypass turbofan engines. These engines offer high speed and higher fuel efficiency than piston and propeller propellers over long distances.
The thrust of a typical aircraft engine went from 5,000 pounds (22,000 N) (de Havilland Ghost turbo) in the 1950s to 115,000 pounds (510,000 N) (General Electric GE90 turbofan) in the 1990s, and its reliability passed of 40 in-flight stops per 100,000 hours of engine flight to less than one in the late 1990s. This, combined with a decrease in fuel consumption, allowed for the routine transatlantic flight of twin-engine aircraft at the turn of the century, where before a similar trip would have required multiple fuel stops.
In common parlance, the term "jet engine" refers to an internal combustion air jet engine. These typically feature a rotary air compressor driven by a turbine, with the surplus energy providing the thrust via a propellant nozzle - this process is known as Brayton thermodynamic cycle. Jet airplanes use these engines for long distance travel. Early jet aircraft used turbojet engines that were relatively ineffective for subsonic flight. Modern subsonic aircraft usually use more complex high-bypass turbofan engines. These engines offer high speed and higher fuel efficiency than piston and propeller propellers over long distances.
The thrust of a typical aircraft engine went from 5,000 pounds (22,000 N) (de Havilland Ghost turbo) in the 1950s to 115,000 pounds (510,000 N) (General Electric GE90 turbofan) in the 1990s, and its reliability passed of 40 in-flight stops per 100,000 hours of engine flight to less than one in the late 1990s. This, combined with a decrease in fuel consumption, allowed for the routine transatlantic flight of twin-engine aircraft at the turn of the century, where before a similar trip would have required multiple fuel stops.