When we study propellers we know that they are affected by the efficiency of propulsion related to the a/c speed. Jet engine instead aren't.
Why the fan stage is not considered to be the same as a propeller.... the only difference looks to be the number of blades!!!! hence it should behave as a propeller!!!!
The turbofan should have a great dependency on the a/c speed too... instead it doesn't.... why?
The aerodynamic profile of a fan blade is slightly different from a propellor. (As they have different design aims)
A propellor is designed to produce most of the forward thrust of an engine whereas a fan blade is designed to be a integral part of the compressor (speeding up the air and compressing it at each succesive stage) . The front fan of a bypass engine is simply the first stage of the compressor albeit large one. This allows a larger portion of the resultant airflow to pass the main core/combustion process