Air fuel ratio in a jet engine

It used to be that tuning a hot street engine or race motor was one of those black arts that only those carburetor and ignition wizards seem to understand. When (and why) an engine needed more or less fuel was a gray area that only those guys who seemed to be plugged into the engine could figure out. Well gang, air-fuel ratio tuning just got a whole bunch easier.

A few years later, companies like Bosch and NTK began building wide-band oxygen sensors that could accurately deliver dependable air-fuel ratio readings in useful ranges for the performance tuner. The problem was these sensors were verrry expensive. But with advanced technology and time, these prices have come down, making a handheld device for reading and data-logging air-fuel ratio finally affordable. Enter Innovate Engineering with an air-fuel ratio meter for a mere $350.

Innovate Engineering has created a slick, digital handheld air-fuel ratio meter that can also data-log the information that will give you immediate and accurate drive-time results that you can use to help tune your engine. The system uses a five-wire Bosch heated oxygen sensor that is intended for use only with unleaded fuels to create the air-fuel ratio readout. At this time, the system is capable of data-logging only the air-fuel ratio, but by the time you read this, Innovate should have released auxiliary components that will allow you to data-log several other inputs, including rpm, coolant or inlet air temperature, and pressures.

A jet engine is a reaction engine discharging a fast-moving jet that generates thrust by jet propulsion . This broad definition includes airbreathing jet engines ( turbojets , turbofans , ramjets , and pulse jets ) and non-airbreathing jet engines (such as rocket engines ). In general, jet engines are combustion engines.

In common parlance, the term jet engine loosely refers to an internal combustion airbreathing jet engine . These typically feature a rotating air compressor powered by a turbine , with the leftover power providing thrust via a 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 which were relatively inefficient for subsonic flight. Modern subsonic jet aircraft usually use more complex high-bypass turbofan engines . These engines offer high speed and greater fuel efficiency than piston and propeller aeroengines over long distances.

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 one 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 before a similar journey would have required multiple fuel stops. [1]

Jet fuel , aviation turbine fuel ( ATF ), or avtur , is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines . It is colorless to straw-colored in appearance. The most commonly used fuels for commercial aviation are Jet A and Jet A-1, which are produced to a standardized international specification. The only other jet fuel commonly used in civilian turbine-engine powered aviation is Jet B, which is used for its enhanced cold-weather performance.

Jet fuel is a mixture of a large number of different hydrocarbons . The range of their sizes (molecular weights or carbon numbers) is defined by the requirements for the product, such as the freezing or smoke point. Kerosene -type jet fuel (including Jet A and Jet A-1) has a carbon number distribution between about 8 and 16 (carbon atoms per molecule); wide-cut or naphtha -type jet fuel (including Jet B), between about 5 and 15. [1]

Fuel for piston-engine powered aircraft (usually a high- octane gasoline known as avgas ) has a low flash point to improve its ignition characteristics. Turbine engines can operate with a wide range of fuels, and jet-aircraft engines typically use fuels with higher flash points , which are less flammable and therefore safer to transport and handle.

Foto:

air fuel ratio in a jet engineair fuel ratio in a jet engine

Video: