Flame in microgravity--
microgravity.grc.nasa.gov
Combustion physics—the science of fire—is an important area of study within NASA, especially at Glenn Research Center in Cleveland, Ohio. Scientists and researchers from NASA, academia, and private industry conduct experiments in microgravity (also called "low gravity") in order to learn more about fundamental combustion phenomena. The more we know about fire, the more we can control it and save lives, property and money.
microgravity.grc.nasa.gov
Flameballs
For years scientists have been conducting experiments on flames at low gravity—a condition called "microgravity"—by using drop towers and aircraft flying parabolic trajectories. These experiments have demonstrated a variety of new combustion phenomena which are hidden by the effects of gravity.
One of the more remarkable findings of these experiments was the discovery of "flame balls," tiny, stable, stationary, spherically symmetric flames that occur in combustible gas mixtures having low Lewis-numbers, and only in microgravity. Dr. Paul Ronney, a scientist at USC, made the discovery in 1984 during a drop tower experiment. Dr. Ronney expected to see an expanding, spherical flame; instead the flame broke into individual balls that burned separately, without shrinking or dividing. These flame balls had never been observed before, although the phenomenon had been hypothesized (unbeknownst to Ronney at the time) in 1944 by the Russian physicist Dr. Yakov Zeldovich.
Why Study Flame Balls?
Surprisingly, we don't know the answer to the simple question for premixed combustible gases: Why do fires keep burning and what makes them go out? The SOFBALL experiments are designed to help provide an answer. By studying these fireballs—the first-ever balls of flame in space, and in many respects the ideal kind of flame to study—we can acquire a better understanding of near-limit combustion, which may lead to improvements in engine efficiency, reduced emissions, and fire safety. |
