The Turbofan Engine

	The Turbofan Engine


	A high bypass turbofan engine.
	A turbofan engine is basically a turbojet to which a fan has been added. Large fans can be placed at either the front or rear of the engine to create high bypass ratios for subsonic flight. In the case of a front fan, the fan is driven by a second turbine, located behind the primary turbine that drives the main compressor. The fan causes more air to flow around (bypass) the engine. This produces greater thrust and reduces specific fuel consumption.

	A low bypass turbofan engine.
	For supersonic flight, a low bypass fan is utilized, and an augmentor (afterburner) is added for additional thrust.

(Special thanks to GE Aircraft Engines.)