Description: Recent results of fundamental capillary fluidics investigations conducted aboard the ISS have targeted families of geometries with direct application to Liquid Acquisition Devices for low-g propellant management. NASA's exploration goals will demand low-g cryogenic propellant management for the Exploration Upper Stage and other vehicles. The specific geometric requirements of a LAD providing bubble-free cryogenic rocket engine flows of 37L/min may now be readily determined using closed-form expressions validated from archived ISS investigations. In this effort we provide the precise geometric specifications and margins for a passive capillary fluidic LAD for cryogenic fluid management for in-space transportation. We will provide design tools such that dimensions may be tuned to adapt to changes in requirements, propellants, tank geometry, materials, flight, etc. We will employ the SE-FIT software to determine all a/symmetric global minimizing surfaces and myriad stability limits as functions of acceleration environment magnitude and orientation with special considerations for orbit and coast with drag, gravity gradient, spacecraft mass center, and self-gravitation. We will confirm predictions with experiments performed employing accurately-scaled devices in a drop tower. Our long term commercial interest is the broad deployment of our method to design highly configurable devices for a broad range of commercial aerospace tankage uses.

Benefits: The developed Liquid Acquisition Device will have immediate applications within NASA at both the design and subsystem level for cryogenic propellant systems. The design approach is also portable to a variety of passive fluids management operations on spacecraft including storable propellants, thermal control fluids, and water processing systems for life support. Current and advanced systems are being pursued by both NASA and the commercial aerospace industry.

Non-NASA markets include commercial spaceflight, with hopes of terrestrial applications concerning biomedical diagnostics, inkjet printing, microfluidics, and Lab-on-a-Chip technologies. The ability to passively separate and store fluid phases for 100% single phase delivery is a desirable unit operation for a variety of important applications at large scales aboard spacecraft, but at small scales on earth. Our design methodology is appropriate for both environments.