General Electric Affinity

General Electric Affinity. It is a medium-bypass turbofan engine developed by General Electric specifically for supersonic transport aircraft, most notably the Boom Supersonic Boom Overture. The engine represents a synthesis of proven technologies from General Electric's commercial and military portfolios, designed to meet the unique demands of efficient supersonic cruise over land with low sonic boom characteristics. Its development marks a significant step in the resurgence of commercial supersonic flight ambitions in the 21st century.

Development and design

The development of the engine was initiated to fulfill the stringent requirements of the Boom Supersonic Boom Overture airliner, which aims to revive economically viable supersonic travel. General Electric leveraged extensive experience from programs like the CFM International LEAP and the General Electric GE9X, integrating a high-efficiency core with a tailored fan and low-pressure system. A primary design focus was achieving exceptional fuel efficiency during subsonic flight over land, complying with noise regulations at airports like London Heathrow Airport and John F. Kennedy International Airport, and enabling a smooth transition to supersonic acceleration. The design team, drawing from work on engines like the General Electric F110 and General Electric Passport, incorporated advanced acoustic treatments and adaptive cycles to manage the engine's performance across a wide speed envelope. The project involved collaboration with NASA on supersonic propulsion research and aimed to meet environmental standards set by the International Civil Aviation Organization.

Specifications

The engine is a twin-spool, medium-bypass turbofan. It features a composite fan derived from technology used in the General Electric GE9X, which powers the Boeing 777X, and a high-pressure core closely related to the CFM International LEAP engine found on aircraft like the Airbus A320neo and Boeing 737 MAX. Specific thrust ratings are tailored for the Boom Overture mission but are classified; however, it is designed to produce approximately 16,000–18,000 pounds of thrust. Key components include blisk compressors, a TAPS III combustor for reduced emissions, and ceramic matrix composites in the turbine section, technologies proven in the General Electric GEnx and General Electric GE9X programs. The nacelle and exhaust system are engineered for supersonic inlet operation and noise suppression, adhering to Stage 5 noise standards.

Operational history

The engine completed its first full engine test run in 2018 at General Electric's facilities in Evendale, Ohio. Since then, it has undergone extensive ground testing, including performance mapping, acoustic testing, and endurance runs, to validate its design for the Boom Overture program. While the Boom Overture aircraft has not yet entered service, the engine's testing regimen has been a critical path item for the program's timeline. The development pace has been influenced by the financial and technical challenges faced by Boom Supersonic, including shifts in partnership strategies and the impact of the COVID-19 pandemic on the aviation industry. Its operational entry awaits the first flight and subsequent certification of the Boom Overture, which targets entry-into-service in the late 2020s.

Variants

As of current information, only one baseline variant has been publicly detailed, developed specifically for the Boom Overture. However, General Electric has indicated the engine architecture is scalable and could be adapted for other supersonic or high-speed applications. Potential future variants could differ in thrust rating, bypass ratio, or specific features for military or business jet applications, following a pattern seen in other engine families like the Pratt & Whitney F135 or Rolls-Royce Trent. Studies for applications such as a potential supersonic United States Air Force executive transport or a high-speed DARPA project could leverage this core technology.

Category:Aircraft engines Category:General Electric aircraft engines Category:Turbofan engines