The German research team acknowledges support through an award from the NASA Research Announcement NRA-94-OLMSA-05 and is currently supported financially by the German Federal Ministry of Economics and Technology (BMWi) via the German Aerospace Center (DLR) under Grant No. 50WM1145. The U.S. research team acknowledges support through an award from the NASA Research Announcement Microgravity Fluid Physics: Research and Flight Experiment Opportunities (NRA-98- HEDS-03) and is currently supported in part under NASA cooperative agreement NNX12AO47A.
Physical Review E
Reduced gravity environments -- Fluid dynamics, Capillary flow, Gas-liquid interfaces
In the near-weightless environment of orbiting spacecraft capillary forces dominate interfacial flow phenomena over unearthly large length scales. In current experiments aboard the International Space Station, partially open channels are being investigated to determine critical flow rate-limiting conditions above which the free surface collapses ingesting bubbles. Without the natural passive phase separating qualities of buoyancy, such ingested bubbles can in turn wreak havoc on the fluid transport systems of spacecraft. The flow channels under investigation represent geometric families of conduits with applications to liquid propellant acquisition, thermal fluids circulation, and water processing for life support. Present and near future experiments focus on transient phenomena and conduit asymmetries allowing capillary forces to replace the role of gravity to perform passive phase separations. Terrestrial applications are noted where enhanced transport via direct liquid-gas contact is desired.
Conrath, M., Canfield, P. J., Bronowicki, P. M., Dreyer, M. E., Weislogel, M. M., & Grah, A. (2013). Capillary channel flow experiments aboard the International Space Station. Physical Review E, 88(6), 063009.