Re: refutation of the scoop theory

[brian whatcott <inet@INTELLISYS.NET>]

At 10:36 8/21/99 -0400, John Denker wrote:
> ... Consider two airplanes with reasonably long wings, initially flying
> in formation, wingtip to wingtip.  Then they move apart, maintaining
> constant airspeed at all times.  When they move apart, there is an increase
> in the induced drag force.  This is fundamentally a nonlinear effect.  It
> is not a small nonlinearity;  there is (to a good approximation) a 100%
> increase in induced drag.....

This reminds me of an observation you may well make as an airline user.
 Looking along the upper surface of the wing, you sometimes see a thin
'wall' in the chordwise direction.
     These fences are put in place to hinder the span-wise direction of
 airflow which may happen at low speeds.
 They can effectively reduce drag, so that some designers fitted end plates
to straight-cut wing tips as a drag reduction measure.


brian whatcott <inet@intellisys.net>
Altus OK