> I agree that the lift will not be identical for the rectangular
> and circular plates. But it's second order effects such as induced
> drag.
You're getting mixed up between lift and lift coefficient. Forget the
second order effects...the area of a circular and rectangular plate is
different (assuming same max chord) so the lift is different.
> We don't have lift reduction of each spanwise element
> pro****tional to the (square of the) local angle between the flow and
> the leading edge--which seems to me to be analogous to the sweep
> angle.
It's not analogous. The sweep angle isn't between the leading edge and
the
the flow direction, it's between the chord line and the flow direction...a
tapered wing can have zero sweep (like a sail plane). A circular plate
has
zero sweep, even though the leading edge angle is very high near the
edges.
> So if a small spanwise element doesn't suffer a lift dropoff
> according to its apparent sweep, why does an entire wing?
Small spansize elements do loose lift as they're swept, because the
chordwise airlow drops. In the example you're talking about (rectangular
or
circular plates) there's no sweep, so no lift drop.
Tom.
