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Bill Beaty wrote:
The Airfoil-Lifting-Force article from QUANTUM magazine is now online on
Jeff Raskin's website:
http://freebie.cfcl.com/jef/
Bill,
On 13DEC95, I wrote a criticism of this article for Phys-L readers. Again, I
would strongly urge readers of Raskin's logic to add lots of salt before
believing any of Raskin's claims.
In short, Raskin uses air jets which are smaller than the wing object. This
can be totally misleading. E.g. blow through in inverted small (5mm) funnel
and you can hold a ping-pong ball inside the funnel...but with a downward
blast of ping pong ball diameter, there's no lift for the ball to stay in
the larger funnel.
Raskin never mentions circulation because he cannot have much with flow
only over the top of the wing.
With circulation, flows over the wing are much larger than those under
the wing, so the 2% figure only shows that he needed circulation in his
model to get the better velocity estimates.
Raskin claims that the back of the airfoil is most important, but the
primary pressure lift profile is at the front third of the typical wing,
where Raskin's arguments would seem to lead to the opposite conclusions.
I have no conformation on the claim about Einstein's wing design or on
Raskin's role in developing the Mac computer...perhaps Jobs or Wosniak can
help on the latter.