You gotta spell things out for us slow kids in the back of the class. Is
the practical relevance that a 40:1 ship becomes a 40:.75? Are you moving
the polar curve, flattening it, both, other? Will it fit in a Christmas
stocking?

Brent

"Jim Hendrix" wrote in message
.. .
Well, here goes. I'll understand, or try to anyway, if my friends, who
used
to think of me as a reasonable, level headed kind of guy, turn and run
when
they see me coming down the street.

Maybe it really didn't happen. Maybe it was only a dream. Maybe it was a
calculation error or equipment failure. Maybe someone who really knows
how
to test aircraft can see a flaw big enough to make it all go away. Maybe
I'll just end up with egg on my face and that will be that.

But I keep sitting here, looking at this graph, in disbelief. I built the
drag rake, constructed and calibrated the pressure sensor, flew the test
flights, crunched the numbers, plotted the graphs. I can't just write
this
off as a kooky claim by someone I never heard of. You have that luxury,
not
me.

Sumon, Dr. Sinha, my long time friend and hydrodynamics professor at Ole
Miss, told me a few months ago that he thought we could get 25% profile
drag
reduction on my Standard Cirrus wing. "Yea, sure," I thought. "We,ll
see."

He had already demonstrated 18% on an NLF0414F airfoil last year in
Starkville, MS. And we easily got the same number at some airspeeds on
the
first attempt with my glider which has a very different airfoil. "That
was
about it," I thought. "We lucked into the sweet spot and we probably
can't
do much better than that."

Then, two days ago, last Saturday, October the 18th, Sumon thought he'd
try
a little modification. I knew before landing that there was some
improvement, about 0.12 volts on the pressure sensor at 100 kts and much
smaller improvements at low speeds. (With this sensor, 1 volt is 1 inch
water gauge pressure.) When I got home and processed the data, there it
was.
We had essentially doubled the drag reduction we were seeing at speeds
over
70 kts and we exceeded 26% improvement at two points, one being the
highest
tested speed, 100 kts. The average from 50 to 100 kts was 23.7%. We had
also corrected a low speed roll off so that we now saw basically flat drag
reductions, as a percentage of clean wing values, at all airspeeds from 40
to 100 kts.

Maybe it's a fluke, some huge error. Maybe we won't be able to repeat it
and that will be that. Or, maybe it's real.

For the full details you can take your browser to www.oxaero.com and click
the Sinha Deturbulator and Test Results links.

So there it is. Don't expect me to defend it. I'm happy to let time be
the
judge.

Fire away!