What are transonic airfoils, and what is the active clearance control? Check out our technical dictionary and find out more about engine technology terms – from active clearance control to velocity triangle.
Thermal barrier coatings
Total stage efficiency
In turbofan engines only a small part of the thrust is generated in the core engine, i.e. compressor, combustion chamber and turbine. The major part is produced by the bypass flow through the fan and the low-pressure turbine. The fan feeds large air volumes downstream which surround the engine like an envelope and thus reduce the engine noise. With increasing bypass ratio, i.e. ratio between internal and external airflow, operating cost, emissions and noise are reduced. Bypass ratios of turbofans for modern airliners are now about 6:1, i.e. the bypass flow through the fan and around the engine is six times the airflow through the core engine.