>> 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.
The assumption was the same area, hence the span and/or max chord
must be different. Let's assume the same chord and that the max chord
is lower on the rectangular plate.
>> 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.
That's the point I was trying to make...how does the airflow
"know" where the chord is? All it "knows" is the angle between itself
and the leading edge. (And I think we are agreeing that that
shouldn't make a difference...)
>> 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.
