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Re: AAPTApparatus Competition [ A cart and a fan (not exactly physics of flight) ]



At 19:25 8/11/99 -0500, Mike Moloney wrote:
I was in charge of the AAPT Apparatus Competition this year in San
Antonio, and have put the entire competition on the web
...
Two of the entries by Bill Franklin relate to the physics of air
movement, and so have something (at least vaguely) with the physics
of flight.

.... When the air stream
is directed toward this plate, the stream is deflected back away from
the curved edge of the plate. In this picture the air would
'rebound' to the right, and the cart would travel to the left.
Reversing the direction of the plate reverses the motion of the cart.


*** Though Mike describes it in undramatic terms, I will add
that this is a practical example of a ship mounted fan, which by
blowing air into the 'sail' pushes the boat forwards. Delightful!

Further down in the pictures you will find Bill's Magnus effect
demonstrator, in which a rotating two-liter pop bottle on a cart
shows this effect. [Point a fan at the rotating bottle, and the cart
moves sideways, due to the Magnus effect.]
...
Mike Moloney, Dept of Physics & Applied Optics, Rose-Hulman Institute
of Technology

***In browsing the exhibits, I ran into this interesting text,
which I think originated with Bill Franklin:
==============================================================
While searching for a picture of Flettner’s ship, I found an
excellent resource for the Magnus effect, as well as many other
topics related to lift and flight. It is a soon to be published
book, See How It Flies, (ISBN 7016405) by John Denker.
It will be available from McGraw Hill for about $35. It is
currently available on the internet at:

http://www.monmouth.com/~jsd/fly/how/htm/title.html#mytoc

This is the address for the main menu; chapters can be accessed
from there.

===============================================================

***I was struck again by Denker's helpful text and illustrations.
I was particularly pleased to see a representation of the airflow
over an inverted asymmetrical airfoil.

(Color bars marking the time-tagged air flow over and under the
foil showed cross-hatching, at least on my color monitor which
took something away from the stream line directionality however)

The personality of the author was in no way obtrusive there.



brian whatcott <inet@intellisys.net>
Altus OK