Who else here knew this? I had thought it was a very basic and clearly understood process in physics, but apparently not. I have included a few snapshots from the article but I suggest reading the full version in the Scientific American link below. It's a good read, not too long (and I recommend SA to anyone who likes to geek out about science and physics as I suspect most lovers of flight do).
On a strictly mathematical level, engineers know how to design planes that will stay aloft. But equations don't explain why aerodynamic lift occurs.
There are two competing theories that illuminate the forces and factors of lift. Both are incomplete explanations.
Aerodynamicists have recently tried to close the gaps in understanding. Still, no consensus exists.
https://www.scientificamerican.com/arti ... n-the-air/
, however, leading aerodynamicist Doug McLean has attempted to go beyond sheer mathematical formalism and come to grips with the physical cause-and-effect relations that account for lift in all of its real-life manifestations. McLean, who spent most of his professional career as an engineer at Boeing Commercial Airplanes, where he specialized in CFD code development, published his new ideas in the 2012 text Understanding Aerodynamics: Arguing from the Real Physics.
Considering that the book runs to more than 500 pages of fairly dense technical analysis, it is surprising to see that it includes a section (7.3.3) entitled “A Basic Explanation of Lift on an Airfoil, Accessible to a Nontechnical Audience.” Producing these 16 pages was not easy for McLean, a master of the subject; indeed, it was “probably the hardest part of the book to write,” the author says. “It saw more revisions than I can count. I was never entirely happy with it.”
And McLean's explanation in a nutshell:
The wing pushes the air down, resulting in a downward turn of the airflow. The air above the wing is sped up in accordance with Bernoulli’s principle. In addition, there is an area of high pressure below the wing and a region of low pressure above. This means that there are four necessary components in McLean’s explanation of lift: a downward turning of the airflow, an increase in the airflow’s speed, an area of low pressure and an area of high pressure.
But it is the interrelation among these four elements that is the most novel and distinctive aspect of McLean’s account. “They support each other in a reciprocal cause-and-effect relationship, and none would exist without the others,” he writes. “The pressure differences exert the lift force on the airfoil, while the downward turning of the flow and the changes in flow speed sustain the pressure differences.” It is this interrelation that constitutes a fifth element of McLean’s explanation: the reciprocity among the other four.
But there is disagreement on this as noted in the article. Pretty cool to learn this, that flight is still a mystery (in science).