Page 62 - International Space Station Benefits for Humanity, 3rd edition.

and n-dodecane (nC12). Researchers measured the
separation of these chemicals, and calculated the
Results from space station fluids numbers for the Soret effect for these chemicals.
investigations have allowed Because the Soret effect occurs in underground
oil reservoirs on Earth, the results will help us better
investigators to compile a video understand the behaviors of similar components
database of capillary and fluid in these reservoirs (Mialdun et al., 2018).
flows in microgravity. In recent combustion studies on the space station,
cool flames were observed unexpectedly following
the radiative extinction of burning fuel droplets.
This result was not predicted by computational models
(based on high-temperature chemistry) nor expected,
and has opened up new areas of combustion
environment allows different physical properties to research in space. Results such as these can lead to
dominate systems, and these have been harnessed for a better understanding of both low and intermediate
a wide variety of investigations in the physical sciences. temperature fuel chemistry and effects on droplet
Invention of modern materials for different applications combustion, with implications for spray combustion
is based on complex fundamental studies. Results of and fire safety (Nayagam et al., 2015). Studies of
materials tested in the unique electromagnetic levitation burning solid materials show that when the opposed
furnace on the space station have provided data on a flow velocity is increased, the flame spread rate first
wide class of materials such as magnetic, constructive increases, and then decreases. This was predicted
and amorphous alloys that can be used in many theoretically but had never before been observed
practical applications, including coatings with reduced experimentally. Data such as these suggest that
friction coefficient, high corrosion resistance, strength microgravity could pose a higher fire risk and a more
and wear capacity (Krivilyov et al., 2012; Krivilyov and difficult fire suppression, which would have significant
Fransaer, 2012). Investigators on the space station implications for spacecraft fire safety (Link et al., 2018).
discovered that when melted metals are cooled down Controlling the flow of fluids is a challenge in
in extremely low temperatures and kept away from microgravity, which hampers the design of systems
surfaces, such as inside the electromagnetic levitator, such as liquid propellants, thermal control and
the dendrites of crystals grow very fast. In addition, waste-water management. However, capillary
a higher concentration of the element in the metal forces, which draw fluids up a narrow tube, continue
(i.e., aluminum) leads to different dendrite growth
characteristics. These results suggest that
measurements in microgravity are important in
understanding how solidification of metals take
place (Fecht et al., 2017). In studies of crystallization
of metallic alloys, different growth patterns and
evolution of microstructures have helped us to better
understand the physical principles that govern
solidification. These structures play a critical role in
the physical properties and behavior of metallic
products, and data from ISS solidification of metal
alloys have contributed to models that better predict
position of columnar-to-equiaxed transition of metal
alloys during the solidification process (Zimmerman
et al., 2017).
In ISS studies of colloids, where molecules in fluids
and gases constantly move and collide, effects of
temperature change on such movement (called
the Soret effect) have been measured in the absence Image taken during a BASS-II (Burning and
of gravity, and thus convection. One particular Suppression of Solids - II) experiment flame test.
investigation went to space to measure mixtures Image credit: NASA
of tetrahydronapthtalene (THN), isobutylbenzene (IBB)

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