Capillary channel flow experiments aboard the International Space Station.
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.
Center of Applied Space Technology and Microgravity (ZARM), University of Bremen, Am Fallturm 01, 28359 Bremen, Germany.
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Conrath
Center of Applied Space Technology and Microgravity (ZARM), University of Bremen, Am Fallturm 01, 28359 Bremen, Germany.
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Canfield
Center of Applied Space Technology and Microgravity (ZARM), University of Bremen, Am Fallturm 01, 28359 Bremen, Germany.
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Bronowicki
Center of Applied Space Technology and Microgravity (ZARM), University of Bremen, Am Fallturm 01, 28359 Bremen, Germany.
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Dreyer
Department of Mechanical and Materials Engineering, Portland State University, PO Box 751, Portland, Oregon 97207, USA.
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Weislogel
European Commission, Institute for Energy and Transport, Petten, The Netherlands.
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Grah