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Old December 13th 03, 11:27 PM
Paul Lee
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Peter,

That is certainly nice iformation to know.

But back to my original question - to help the situation.

"..has anyone investigated placing a few vortilons near
outer wing part to compensate for the early tip stall tendency?.."

This could be done with a standard EZ by observing if the bobing stall
frequency increases with addition of a few outboard vortex generators.

Any EZ volunteers out there? Here is the procedu Measure the stall
bobing frequency as a position of CG. Then measure it again after
the few outboard VG's are installed and see if the frequency increases
or decreases with CG position. Would not be very expensive, just time
consuming.

I am building a SQ2000 canard but KLS Composites has designed
the thing so that there is no bobing stall frequency - it simply descends
at a constant rate. KLS demonstated that to me in their factory bird.
So I can't do the test - at least in the same way.

----------------------------------------------------
Paul Lee, SQ2000 canard project: www.abri.com/sq2000

Peter Dohm wrote in message ...
My recollection, from an aerodynamics class long ago, is that the tendency
of a wing to stall first at the tip and progress inward is not a function
of sweep. The sweep just makes it LETHAL.

Assuming that the wing has no twist, also known as wash-out, and that the
wing is well constructed and finished; then:
1 A straight (Hershey Bar) wing will stall from the root outward.
2 An elliptical wing will stall all at once.
3 A radically tapered (2:1) wing will stall from the tip inward.
4 A moderately tapered wing will approximate an elliptical wing.

The earlier comment regarding the canard vortex on the Vari-Eze is an
excellent note of caution, as it will tend to simulate reverse wash-out
of the main wing. Therefore, it the main wing was ever allowed to stall,
it could be expected to do so in the manner of a wing with a much more
radical taper ...

BTW, radically swept tapered wings have the reputation of being impossible
to recover from a stall -- if you allow it to occur!

Peter
..

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