The wrong "Bernoulli" explanation in Sci. American for April 2005

A recent issue of Scientific American carries a mind virus! :)

In the "Working Knowledge" column, the author presents an incorrect and
long-debunked explanation of how wings work:

"because the wing top is curved, air streaming over it must travel
farther and thus faster than the air passing underneath the flat bottom.
According to Bernoulli's principle, the slower air below exerts more force

on the wing than the faster air above, thereby lifting the plane."
http://www.scientificamerican.com/article.cfm?chanID=sa006&colID=9&articleID=00009993-1F9A-1417-9F9A83414B7F012B


The above explanation is wrong, and is known as the "Equal Transit-Time
Fallacy."    This incorrect explanation is widespread among children's
books, but I'm suprised to see it in a reputable magazine like SciAm.

It's debunked here:
NASA GRC:  Incorrect lifting-force theory #1
http://www.grc.nasa.gov/WWW/K-12/airplane/wrong1.html
http://www.grc.nasa.gov/WWW/K-12/airplane/bernnew.html


Also see other debunkings:
Anderson/Eberhardt: a physical description of flight
http://www.aa.wa****ngton.edu/faculty/eberhardt/lift.htm

Denker: How Airplanes Fly
http://www.av8n.com//how/htm/airfoils.html#sec-inverted-camber

Irrotational inviscid flow: Streamline animations
http://www.idra.unige.it/~irro/profilo1a_e.html

Or just ask yourself this:  if airfoils *must* be more curved on
top, doesn't this prove that symmetrical airfoils cannot work,
and that upside-down flight is impossible?


((((((((((((((((((((((( (  (    (o)    )  ) )))))))))))))))))))))))
William J. Beaty              Research Engineer
beaty@[EMAIL PROTECTED]
     UW Chem Dept,  Bagley Hall RM74
billb@[EMAIL PROTECTED]
              Box 351700, Seattle, WA 98195-1700
ph425-222-5066                http//staff.wa****ngton.edu/wbeaty/