NASA Technical Reports Server (NASA) · 2008 · 19 citations · 0 references
Open access
EngineeringAerospace EngineeringFluid MechanicsPropulsionShip PropulsionPropellant ChemistryPropulsion SystemsVehicle Propulsion SystemsCryogenic PropellantsLiquid PropellantsNormal Gravity FieldPropellant Management DevicesPropellant Mass AccountingPropellant Tank DesignSpecific Gravity
Gauging propellant mass in low gravity is challenging because liquid configuration is uncertain and multiple ullage bubbles may form, and although several concepts have been tested, no flight‑proven reliable system exists. NASA sought a database of gauging techniques used in vehicles during ascent, settled, and short coasting periods for both cryogenic and storable propellants, and a review of past and current R&D applicable to low‑gravity conditions. The report documents the results of that survey.
Gauging the mass of propellants in a tank in low gravity is not a straightforward task because of the uncertainty of the liquid configuration in the tank and the possibility of there being more than one ullage bubble. Several concepts for such a low-gravity gauging system have been proposed, and breadboard or flight-like versions have been tested in normal gravity or even in low gravity, but at present, a flight-proven reliable gauging system is not available. NASA desired a database of the gauging techniques used in current and past vehicles during ascent or under settled conditions, and during short coasting (unpowered) periods, for both cryogenic and storable propellants. Past and current research and development efforts on gauging systems that are believed to be applicable in low-gravity conditions were also desired. This report documents the results of that survey.