NELLI News - Windtunnel Trip
NELLI BLOWS INTO CAMBRIDGE
CLUB PRESIDENT DENIES HE'S FULL OF HOT AIR
On Saturday, January 18, 2003, a group of NELLI members met at MIT in Cambridge, Mass., for a seminar and demonstration of the world famous Wright Brothers Wind Tunnel given by Club President Dick Perdichizzi. The University has a number of wind tunnels, but the biggest is the Wright Brothers, measuring about 8' in diameter in the inner vessel. The tunnel itself is surrounded by an outer vessel that can be sealed and can exert up to four atmospheres of pressure on the tunnel. Without getting into a lot of technical explanations, suffice it to say that the ability to run the tunnel under pressure allows for additional kinds of testing to be done.
The Wright Brothers wind tunnel is an Eiffel design,
and yes it is patterned after an original design by Alexandre Gustave
Eiffel who designed the famous tower in Paris. It is a complex
design and has the ability to deliver air that is free of any
turbulence and at controlled speeds and pressures. The test chamber
is equipped with an array of sensors from which the data is
collected. MIT tests all sorts of things, many for the U.S.
government, including aircraft, cars (there was a recent project for
Ferrari road cars), sports equipment and in particular, buildings.
It turns out that all modern large buildings now undergo wind tunnel
testing.
Of course, being a Lotus car club, we had to do a little testing of our own, so first we set up an early Lotus FPC (formula pedal car). The bits of yarn that were attached to the nose showed a nice laminar flow, but the cockpit and engine definitely needed some work. A smoke wand inserted through a port in the tunnel side gave a good visual idea of the air flow. From the windshield back it was nothing but turbulence. This test was done at a windspeed of about 30mph, which would require an Olympic pedal car driver to match.
Hot on the trail of scientific breakthrough, we next set up Foster
Cooperstein's 1/6 scale Elise. The model was not yet assembled, and
the body still unpainted. If the real thing is as slippery as the
model, the Lotus boys have been doing their homework. The drag
coefficient was something like .03.
Everyone had a great time poking around looking at the many projects that have been created by students and faculty, like a miniature rocket motor, or the world speed record human powered watercraft. The day ended at the local micro brewery for burgers and a couple of ales. All in all a great winter outing. Thanks Dick!!
Last Updated: December 22nd, 2002