In a turbofan engine, how is the fan driven?

In a turbofan engine, the fan is primarily driven by the low-pressure turbine, which is connected to the low-pressure compressor. The fan and the low-pressure compressor are part of the same spool orshaft in many turbofan designs, allowing them to operate together. This configuration enables the engine to efficiently convert the energy produced by the turbine into thrust, primarily through the movement of air by the fan.

The low-pressure turbine extracts energy from the exhaust gases to power the fan, while the high-pressure turbine works in conjunction with the high-pressure compressor to compress the incoming air further. This two-spool design helps optimize performance and efficiency across different operating conditions. The integration of the low-pressure turbine with the fan is crucial in ensuring that the turbofan engine consistently delivers the thrust required for efficient flight.