Performance of the turbofan engine lies in between the turboprop engine and the turbojet engine.
It is similar to turboprop engine in working with following differences:
- Bypass air ducted in case of turbofan is much less compared to turboprop engine.
- In this case, the bypass air is accelerated by a fan instead of the propeller.
- Both the bypassed air and the main air passing over the turbine are mixed before the entry to the nozzle in case of turbofan engines.
Schematic diagram of the turbofan engine is as shown above.
Working of the turbofan engine is similar to turboprop engine wherein the gas turbine drives compressor and the propeller.
It works by accelerating large volumes of air to moderate velocities.
The turbofan engine offers good economy at low jet velocities along with good propulsive efficiency.
These engines are suitable for civil aviation aircrafts which fly at sub sonic speeds.