How Does Wing Shape Affect Airplane Lift and Pressure Differences?

[boneh3ad]

Not mathematically, but there are popular articles that include a description of how a wing works from the perspective of a ground based observer (assuming no wind) or from the air's frame of reference as well as from the wings frame of reference. A couple of articles with a "macroscopic" of how wings work that should answer the questions in the original post.

And yet none of them actually refutes that Bernoulli's equation is valid for calculating lift. Treating the airfoil from the stationary observer's frame of reference is a curiosity and can illustrate a couple of interesting things, but in terms of actually modeling or calculating lift, it is very inconvenient and rarely used.

 

[rcgldr]

I think this thread went off on a tangent into the details (like Newton versus Bernoulli, when in fact both apply), when it seems the original post was asking for a more generic description of how wings work, like why a flow follows a convex surface which was explained in post #47 (I call this void theory, air accelerates into what would otherwise be a void ... ). Getting back to the original post:

I'm confused about how an airplane generates lift. If I'm correct the wing of the plane is bent so air can flow over the top of the wing faster than the bottom of the wing, the faster fluids somehow apply less pressure resulting in a net upward force. Why though does a bent wing allow air to flow faster over the top, and why do fast moving fluids apply a lesser pressure than slow ones?

Assuming bent wing means curved wing, this isn't required. A flat wing can produce lift, and for small balsa type models, it's good enough. Curved wings are more efficient (less drag for the same amount of lift).

As for faster flow over the top of a wing, this only applies from the wings perspective (or anything moving at the same speed as the wing, like the pilot in an aircraft). It's because a wing draws the air downwards from above (see post #47 for why this happens) reducing it's pressure and pushes it downwards from below increasing it's pressure. Air accelerates as it moves from a higher pressure zone to a lower pressure zone, and decelerates when it moves (due to momentum) from a lower pressure zone to a higher pressure zone. So higher speeds coexist with the lower pressure zones above a wing, and lower speeds coexist with higher pressure zones below a wing.

For an observer on the ground (with no wind), again you have the wing drawing air downwards from above and pushing air downwards from below, but the fastest moving air occurs just behind the trailing edge of the wing, mostly downwards (related to lift) and somewhat forwards (related to drag).

For an example of an unusually shaped wing, here's a video of a prototype reentry vehicle called a M2-F2:

 

[stedwards]

"...and why do fast moving fluids apply a lesser pressure than slow ones?"

I should have found this answered in wikipedia bernoulli as the conservation of energy
equation, E = T+V pertaining to an element of fluid, rather than the oblique reference
to Newton.