Charlie Springer wrote:
On Sat, 20 Aug 2005 16:31:43 -0700, wrote
(in article . com):


Here's some news that recently came out:

http://www.newscientist.com/article.ns?id=dn7867

http://abc.net.au/science/news/stories/s1439827.htm

Apparently, soundwaves can help airflow stay near the wing and increase
lift. This can help smaller aircraft to avoid stalling at lower
airspeeds. Is this a technology that could be usefully applied to
existing small aircraft? Or would it require some totally new design
thinking?



I have some of the piezo polymer film they were probably using (from SONAR
experiments, and a steel plate target that tells you where the bullet hit).
The amplitudes would be very small, but covering a wing on an RV or Bonanza
would be less than five pounds in weight, including the high voltage
electrics needed for the piezoelectric material.

But New Scientist is not the most reputable source (called New Age Scientist
by some, ignored by the rest) and I would have to see this confirmed by
another lab. It smells a lot like the kind of signal that screws up your
instrumentation. The drive for the film is likely 800 to 1,200 volts and at
400 Hz running on a little model in a wind tunnel with sensitive detectors of
various sorts. I'll just say I'm skeptical.

-- Charlie Springer


No need to be skeptical on this on Charlie. The technique will work.
Unfortunately, the five pounds of high-maintainence, active equipment
can be replaced with a few ounzes of turbulator strips.

I read one of the NASA reports, done YEARS ago, on the Larc website.
They used the same techique, using sound waves to re-energize the
boundary layer. Pointless was their conclusion if I remember correctly.


--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."