I am in the middle of my PPL(A) theory and I am experiencing a mental breakdown studying propellers. Until yesterday I was happily living in my ideal world where I was sure I really understood all the relevant aspects and details about how propellers are designed and actually work.
Then today I stumbled upon a webpage that destroyed all my self-confidence with just 2 out of 3 sentences:
Firstly, the shape of the propeller is such that it cork screws through the air. The cork screw motion pulls the propeller and the plane through the air
Ok, I thought this was just a huge misconception. I thought propeller blades, as aerofoils, generated Lift and Induced Drag, which we consider as Torque and Thrust in relation to the rotational plane for a number of reasons. All this having nothing to do with "cork screwing into the air" for the same reason why a wing doesn't go up because it cork screw itself into the airflow. It simply generates Lift. Is there something I am missing?
Secondly, the propeller spins at high speeds pushing air back and thus pushing the plane forward. The more air that is pushed back the more the plane is pushed forward
Ok.. no. I really thought this was how a jet engine works, not a propeller. Again, I must be missing a LOT.
Thirdly, [...] the blades are actually wings that spin around. The curved surface of the blades face the front of the plane and this creates a low pressure region in front of the plane sucking it forward
Now, since I believed only the 3rd point made sense, are the first 2 described effects real?