As the International Space Station enters its third decade of continuous human presence, the impact of microgravity research conducted there keeps growing.
Flame Design, part of the Advanced Combustion via Microgravity Experiments (ACME) project, studies the production and control of soot. Because soot can adversely affect the efficiency and emissions from flames and equipment lifetime, results could lead to more efficient and cleaner burner designs. The experiment is conducted with spherical flames of gaseous fuels in the Combustion Integrated Rack (CIR).

Researchers reported a number of observations in a paper published in Combustion and Flame Journal, including rate of growth in flames, coupling of burner heating and flame radius, oscillations as flames start to go out, relationship between fuel flow rates and flame temperature, and irradiance in flames with increasing or nearly constant peak gas temperature. These observations enhance the understanding of fire behavior and could help keep people safer in spacecraft and on Earth.

Here, a flame ignited as part of Flame Design. The yellow spots are soot clusters that glow yellow when hot. These clusters grow larger in microgravity than on Earth because the soot remains within the flame longer.

This is just one of the many things learned on the International Space Station this year.

Image Credit: NASA Larger image