> the air that moves faster across the top of a wing.
Except absolutely flat wings also work where the air is traveling the same distance. They aren’t nearly as efficient, but still produce lift.
Wings shape relates to skin effects, vortexes, turbulence, and drag. There’s a lot of complex interactions involved which don’t simplify to faster moving air creates lift.
Does that flat wing work with a zero angle of attack (that is, parallel to the ground) or does it have to point upwards?
Race cars use downward pointing wings to generate the opposite of lift, to push the car into the ground. Of course even car wings have evolved into more efficient shapes, because there is a competition to win those races.
All wings need a positive or negative when upside down angle of attack to generate lift. People often draw the cord line incorrectly because the flat part of a wing isn’t zero and wings are mounted with a positive angel of attack so aircraft can be level in flight even with a ~15 degree angle of attack.
Car aerodynamics is complicated. People talk about spoiler downforce without really considering the details. If you push down on the rear spoiler of a toy F1 car the front end lifts up because it’s located behind the rear wheel. The goal is specifically downforce on the rear tires.
Similarly the rotational force on an axle wants to lift the front end. There’s another torque from the tires being located below the force of drag which again wants to lift the front of a car.
For strait line dragsters they accept the front wheels having reduced contact with the road for improved acceleration because they don’t need to turn. Where Indy and F1 uses front wings, but winged sprint cars pushed the classic spoiler forward on top of adding a wing for additional control. In racing it’s all about different trade offs for each sport.
I should have said to generate lift in level flight. Drop anything with air resistance and it’s technically generating lift. However it’s important to separate the angle of attack relative to the airstream vs angle of attack relative to the ground for falling objects.
Anyway non-semmetric airfoils are about efficiency when the aircraft never flies upside down. Unfortunately you occasionally see mislabeled diagrams where the angel of attack seems to be zero when the wing is laying flat rather than the leading and trailing edge being level which creates a great deal of confusion.
Except absolutely flat wings also work where the air is traveling the same distance. They aren’t nearly as efficient, but still produce lift.
Wings shape relates to skin effects, vortexes, turbulence, and drag. There’s a lot of complex interactions involved which don’t simplify to faster moving air creates lift.