Centaur propellant thermal conditioning system

An upgraded Centaur capability was studied by investigating three main areas: (1) Analytical and experimental investigation of promising capillary pumping concepts for passive cooling of cryogenic capillary acquisition devices resulted in selection, test, and empirical correlation of four wicking configurations. Only plate/screen-screen/plate and plate/screen-plate/screen configurations would function successfully under worst-case Centaur D-1S conditions. Weight estimates were developed for the passively cooled configurations and comparisons were made of passive and actively cooled capillary devices. (2) Thermal subcoolers for replacing pressurization and boost pump systems for three engine candidates and three Centaur D-1S missions were evaluated for several feed system configurations. Analysis included both transient and steady-state operation. Weight comparisons were made among feed system alternatives. (3) Existing experimental mixing studies to destroy thermal stratification were evaluated to determine the best mixing correlation to fit all available data. The correlation was then used to modify a computer program to size thermodynamic vent systems for Shuttle-based Centaur derivatives.