Booth Id:
PHYS040
Category:
Physics and Astronomy
Year:
2020
Finalist Names:
Sigrest, Eleanor (School: Governor's School at Innovation Park)
Abstract:
Slosh is unwanted movement of fuel in a tank, and has caused many failed space missions.
Slosh occurs during spacecraft launch and in microgravity during maneuvers. NASA and
spacecraft developers have spent billions managing slosh. Baffles effectively manage launch
slosh; however, mitigating slosh in microgravity, in which surface energies rule the fluid
dynamics regime, requires costly subsystems that add weight and complexity. This project
describes a novel method to manage microgravity slosh through custom surface energies.
Acrylic tanks were treated with superhydrophobic and superhydrophilic coatings and filled at
various fill fractions. The settling time for the “fuel” in coated tanks was compared to non-coated
(control) tanks after an imposed acceleration. Additionally, fuel aggregation around the sump
was compared between coated and non-coated tanks. Two coating profiles were investigated:
20%/80% superhydrophilic/superhydrophobic, and a 50/50 profile. The experiment was
replicated for tanks with simulated propellant management devices (PMD’s). Microgravity was
achieved through parabolic flight.
This experiment supported the hypotheses with a significant reduction in settling time for coated
tanks. The 50/50 profile performed better than the 20/80. Settling time reductions of 73% for
high fill fractions and 59% for low fill fractions were achieved. The coated tanks aggregated the
liquid at the sump 100% of the time, compared to 12% for the control tanks and 64% for tanks
with PMDs. The results demonstrate a method to eliminate slosh subsystems, reducing cost,
weight and complexity and increasing mission reliability and capacity.