// PROPULSION SYSTEMS AND ENGINE TECHNOLOGY TERM
High-Bypass Turbofan
A high-bypass turbofan is the type of jet engine used on most modern airliners. A large fan in the front pushes the majority of air around the hot engine core, which makes it much quieter and more fuel-efficient for flying at subsonic speeds.
TECHNICAL DEFINITION
A high-bypass turbofan is an air-breathing gas turbine engine featuring a large-diameter ducted fan that accelerates a significant mass of air (bypass air) around the engine's core gas generator. This design, characterized by a high bypass ratio (BPR > 5:1), generates most of its thrust from the cool bypass stream, resulting in high propulsive efficiency, low specific fuel consumption (SFC), and reduced noise, making it optimal for subsonic commercial and military transport aircraft.
BACKGROUND
A turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft propulsion. The word "turbofan" is a combination of references to the preceding generation engine technology of the turbojet and the additional fan stage. It consists of a gas turbine engine which adds kinetic energy to the air passing through it by burning fuel, and a ducted fan powered by energy from the gas turbine to force air rearwards. Whereas all the air taken in by a turbojet passes through the combustion chamber and turbines, in a turbofan some of the air entering the nacelle bypasses these components. A turbofan can be thought of as a turbojet being used to drive a ducted fan, with both of these contributing to the thrust.
READ MORE ON WIKIPEDIASYNONYMS & ALIASES
- fanjet
- HBTF
- bypass engine
- turbofan
- ducted fan engine
- high-bypass ratio engine
USAGE NOTE
This engine architecture is the dominant choice for commercial airliners and cargo planes due to its superior fuel economy at subsonic cruise speeds (Mach 0.7-0.9).
DEVELOPERS
Organizations developing technology related to High-Bypass Turbofan.
A world-leading provider of jet and turboprop engines. They manufacture some of the most powerful high-bypass turbofans, including the GEnx for the Boeing 787 and 747-8, and the GE9X for the Boeing 777X.
A subsidiary of RTX Corporation, Pratt & Whitney is a global leader in the design and manufacture of aircraft engines. Their Geared Turbofan (GTF) engine family is a significant innovation in high-bypass technology, offering improved fuel efficiency and reduced noise.
A pre-eminent British engineering company specializing in power and propulsion systems. Their Trent family of high-bypass turbofan engines powers many wide-body aircraft like the Airbus A350 and Boeing 787. They are also developing the UltraFan, aiming for even higher bypass ratios.
A 50/50 joint venture between GE Aerospace and Safran Aircraft Engines. They produce the CFM56 and the new generation LEAP engines, which are the most common high-bypass turbofan engines for narrow-body commercial aircraft like the Boeing 737 and Airbus A320 families.
A French multinational aircraft engine company. As a partner in CFM International, it co-develops and manufactures the LEAP engine. It also develops military engines and is involved in European advanced propulsion research programs.
Germany's leading engine manufacturer and a key technology partner in numerous commercial and military engine programs. They develop and manufacture critical components, such as high-pressure compressors and low-pressure turbines, for many modern high-bypass turbofans.
A major NASA research facility that conducts extensive research and development in aeronautics and space propulsion. They pioneer advanced concepts for turbofan engines, including composite materials, novel fan designs, and technologies for reducing emissions and noise.
A Japanese engineering corporation that is a significant partner in many international engine programs. They manufacture major modules and components, such as fan blades and low-pressure turbine shafts, for engines like the GEnx and the Pratt & Whitney GTF.