Karman_trefftz

Equal Transit Time is a Fallacy

Hello school teachers and students!

Have you heard the explanation of flight that goes like this?

“The top surface of the wing is curved and therefore has a longer length. The air travelling over the wing has to travel farther so it winds up travelling faster”.

This isn’t true. The molecules that get separated at the front of the wing don’t know or care if they meet at the trailing edge of the wing.

In fact what happens is more like this animation. The top airflow is faster. But it’s actually fast enough that it arrives ahead of the lower airflow. This is the same for a flat airfoil!