What is the function of the large fan in a turbofan engine?

The function of the large fan in a turbofan engine is to pull incoming air and divide it into primary and secondary airflow. This large fan is essential for the engine's operation as it generates most of the thrust required for the aircraft to move forward.

The large fan draws in ambient air, and a portion of this air moves directly into the engine core, known as the primary airflow. The rest of the air bypasses the engine core, referred to as the secondary airflow, which contributes to the thrust without going through the combustion process. This design allows for increased efficiency and reduced noise, which is a significant advantage of turbofan engines over other types of jet engines.

Understanding the role of the large fan is crucial in comprehending the overall functionality of turbofan engines and how they contribute to the performance of modern aircraft.