ORIGINAL: tomfiorentino
OK...thank you for taking the time to write that up.
So, not too oversimplify, but is it safe to assume then that the differences in stall sequence relating to rectangular, tapered and elliptical wings is in turn related to the differences that exist in the way each of those wings generate vortices (and other disturbances)?
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You are welcome, Tom.
I have just added two schematics to Post #10 above for clarity.
I believe that the differences in stall sequence is a simple problem of area and pressure gradient above that area.
In other words, those differences relate to where the cross section (referred as strip in my previous post) that is creating the lowest pressure (on the top surface) is located along the wingspan.
As your book explains (I have one), if you consider each of those strips as a wing with no tip (there is backpressure in both ends or tips), then the area that contributes to lift is directly proportional to the chord (since each strip has the same width or “stripspan’).
From experimentation, we know that the lift force produced by the half-wing decreases exponentially from the root to the tip.
We also know that the lift force produced by each of those strips is proportional to the area of the strip and to the square of the speed at which the wing is moving in the air.
Since all the strips are moving thru the air at the same speed, there are only two things to change in order to obtain different lift from each strip: area and coefficient of lift.
The efficiency of the elliptical wing comes from the fact that it has the surface necessary to create the minimum lift, no one inch less or more.
In order to achieve that ideal, the coefficient of lift of each strip has to have the same value (minimum L/D point).
Then, is the area the only remaining thing to play with.
Because of that, moving from root to tip, the area of each strip is reduced in the same proportion in which the lift reduces itself naturally (due to the infiltrations of air from the bottom of the wing and around the wing tip).
This is achieved only by reducing the chord of each strip, because each of them keeps the original width.
By doing that, and then putting together all those strips, the resulting shape of the half-wing is half an ellipse.
According to the book and other references, an elliptical wing stalls over the whole span at the same time.
The detachment bubble moves from trailing edge to leading edge.
http://www.faatest.com/books/FLT/Cha...ngPlanform.htm