Turbofan Engine

A Turbofan Engine is a type of gas turbine engine in which a large ducted fan, driven by the turbine section, produces the majority of the engine's thrust. The fan accelerates a large mass of air around the core (bypass air), which is more fuel-efficient and quieter than pure turbojet engines.

• Bypass ratio: The ratio of bypass air to core air — modern engines are 'high-bypass' (8:1 to 13:1)
• Examples: CFM LEAP (A320neo, B737 MAX), Rolls-Royce Trent XWB (A350), GE9X (B777X)
• High-bypass turbofans produce 80%+ of thrust from the fan alone
• More fuel-efficient than low-bypass engines at subsonic speeds
• Significantly quieter than early turbojets (critical for noise certification)
• Geared Turbofan (GTF): Pratt & Whitney PW1000G adds a gearbox to optimize fan and turbine speeds independently