> No. What causes lift is the differential in pressure between the top and the bottom surface of the wing.
How do you explain airplanes that can fly with wing with symmetrical cross-section profile?
How do you explain airplanes flying upside-down?
How do you explain airplanes that can fly with wing with symmetrical cross-section profile?
How do you explain airplanes flying upside-down?
The following plot shows the pressure distribution over a wing at 3 different angles of attack [1]. As you can see from the first plot, some lift is created at -8 degrees AOA, but clearly a lot less than the +10 AOA example, as that airfoil is optimized for positive angles of attack.
I've read excellent article debunking the Bernoulli effect and lift many years ago, I'm not sure I can find it again...
The nonsensical part of this model is that a particle on an upper streamline has anything to do with a particle on a lower streamline and that it is trying to keep up with it. Not so of course.
But the lift created by a pressure difference due to a locally faster flow still holds.
> So when you mention AoA you implicitly lead to the explanation that lift, in majority, is not based on the Bernoulli effect.
For a NACA 0012, you'll need an AoA, to have a faster flow on the upper part of your airfoil, as it it symmetric. Other airfoils are perfectly fine creating lift at 0 AoA.
You can make almost anything fly if you have enough power and a tail. But how efficient will it be? Not as efficient as an airfoil that takes advantage of all the fluid motion properties.
> How do you explain airplanes flying upside-down?
Angle of attack is what causes lift. If you have a surface angled against the relative wind, it will produce lift.