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How does a high bypass turbofan work?
The compressor absorbs all the mechanical power produced by the turbine. In a bypass design extra turbines drive a ducted fan that accelerates air rearward from the front of the engine. In a high-bypass design, the ducted fan and nozzle produce most of the thrust.
What is high bypass?
The high-bypass engine (top) has a large fan that routes much air around the turbine; the low-bypass engine (middle) has a smaller fan routing more air into the turbine; the turbojet (bottom) has zero bypass, and all air goes through the turbine.
What is bypass engine?
In a turbofan (bypass) engine, the bypass ratio is a comparison between the mass flow rate of air drawn into the engine through the fan disk that goes around the engine core with the mass flow rate of the air that goes through the engine core.
Why are turbofan engines used in airliners?
To move an airplane through the air, thrust is generated by some kind of propulsion system . Most modern airliners use turbofan engines because of their high thrust and good fuel efficiency. On this page, we will discuss some of the fundamentals of turbofan engines.
How is a high bypass jet engine made?
A fair proportion of the air entering the ½ stage is also ducted to the bypass stream. The two-spool high bypass General Electric CF6 (top half section) is based on the same gas generator and turbine as the TF39 (bottom section) which powers the Lockheed C-5A Galaxy.
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.
Which is more fuel efficient, a turbofan or a jet engine?
Low bypass ratio turbofans are still more fuel efficient than basic turbojets. Many modern fighter planes actually use low bypass ratio turbofans equipped with afterburners. They can then cruise efficiently but still have high thrust when dogfighting.