[(Team FRACTAL members left to right):
Seated: Sam Tun; Matt Moorland; Jennifer Sloan-Warren
Standing: James Caruthers; Craig Miller; Sam Clark; faculty advisor Dave Westpfahl; Eric Nilan; Robin Campos; Maggie Stauffer; and Dave Wilson.
Not pictured: Tech student Vince McIntire and Tech faculty advisor Leonard Truesdell.]
HOUSTON, Sept. 13, 2001 -- Ten New Mexico Tech students traveled this summer to NASA's Johnson Space Center in Houston and took their team-developed experiment to never- before- achieved heights aboard the space agency's famed KC-135A aircraft -- a military version of a Boeing 707 which has been affectionately dubbed by its various passengers over the years as the "Vomit Comet."
Four members of Tech's "Team FRACTAL" accompanied their fluid dynamics experiment aboard the airplane in two separate flights as it made a series of 32 looping parabolic ascents and descents from about 34,000 feet to 25,000 feet above the Gulf of Mexico.
The steep 50-degree dives taken by the aircraft typically result in 25 to 30 seconds of near weightlessness, or "microgravity" conditions, for researchers as they hastily conduct their scientific experiments within the airplane's padded cargo bay.
This ultimate roller-coaster ride aboard the KC-135 also includes equally steep climbs which result in "macrogravity" conditions, subjecting passengers, experiments, and aircraft to nearly 2Gs, or twice the pull of the Earth's gravity.
The increased gravity on the ascents and the reduced gravity on the descents often affect even the strongest stomachs, causing a high-altitude version of motion sickness and earning the Vomit Comet its moniker.
New Mexico Tech's Team FRACTAL (an acronym which stands for "Fractal Response and Character of Turbulence at Low Gs") explored the effects of reduced gravity, as well as increased gravity, on the fractal characteristics of buoyancy driven turbulent flow -- a well-known phenomenon which occurs in various natural systems, such as weather formation in the Earth's atmosphere, the circulation and mixing of ocean waters, and air circulation and ventilation in buildings.
Fractals, in and of themselves, are geometrical figures that can be subdivided into smaller and smaller parts, each of which is a reduced-size copy of the whole.
The experiment devised by the New Mexico Tech students involved immersing a heating element in a narrow tank of water and heating up the water until a convective heat flow became turbulent enough to allow illumination from a nearby light to project the pattern of convection onto a screen located on the other side of the tank. The varying patterns of convection being projected onto the screen were then observed, recorded with a digital camera, and downloaded in a data stream to a laptop computer.
In addition to designing and implementing the fluid dynamics experiment, Team FRACTAL members also developed their own software which they are currenlty using to analyze and evaluate the fractal nature of the observed turbulence.
The Tech students plan to publish results of their work and also conduct educational outreach programs based on their experiment and experiences aboard the Vomit Comet at New Mexico middle and high schools.