Can annular combustion?
Like the can type combustor, can annular combustors have discrete combustion zones contained in separate liners with their own fuel injectors. Unlike the can combustor, all the combustion zones share a common ring (annulus) casing. Each combustion zone no longer has to serve as a pressure vessel.
Why is annular combustion chamber?
Modern combustion chambers are totally annular. The flame tube makes a ring around the entire engine. This results in much higher combustion efficiency- nearly all of the fuel is burned completely. This reduces noxious emissions.
What’s the difference between a turbo and a turbofan engine?
In turbojet and turbofan engines, the turbine is sized to drive the compressor section and fan as appropriate. The higher the combustion temperature, the more energy can be extracted while maintaining the required exhaust velocity and thus thrust at the nozzle.
How does thermodynamic efficiency affect a turbofan engine?
Thermodynamic efficiency is described in the section above in general terms, but in specific, the cooling air available to turbofan engines plays a significant role in their increased performance. In essence, turbofans are able to use some of their thrust as cooling flow for the turbine and combustion sections of the engine.
Where does the air go in a turbofan engine?
The hot exhaust passes through the core and fan turbines and then out the nozzle, as in a basic turbojet. The rest of the incoming air passes through the fan and bypasses, or goes around the engine, just like the air through a propeller. The air that goes through the fan has a velocity that is slightly increased from free stream.
What is the bypass ratio of a turbofan engine?
The ratio of the air that goes around the engine to the air that goes through the core is called the bypass ratio . Because the fuel flow rate for the core is changed only a small amount by the addition of the fan, a turbofan generates more thrust for nearly the same amount of fuel used by the core.