Advance the state-of-the-art for long-term storage of cryogenic fluids in reduced gravity environments by: developing the most promising analytical and numerical models; anchoring the models with new or existing test data; developing the most promising pressure control concepts through a combination of component and system level testing. (TRL ~ 4); and gaining experience with full scale loading/control of potential green propellants for future systems. NASA Centers involved: Glenn, Ames, Marshall, Goddard

Models of cryogenic space systems require several key features to accurately predict the tank thermodynamic & fluid behavior.

Simultaneous time-accurate solution of governing equations in both liquid & gaseous regions Heat transfer between gas/liquid/wall/penetrations Buoyancy effects Variable external heating & acceleration Surface tension effects in low gravity Multi-species ullage gas with noncondensable component (and possible diffusion of noncondensable into liquid) Interface dynamics & slosh prediction Thermodynamic vent systems submodels Turbulence modeling Effect of LADs (if spray bar) Spray atomization, vaporization/condensation, drop interactions with solid surfaces and liquid/ullage interface

Tank Thermal & Pressure Control Modeling

Goal is to advance the state of the art in analysis tools (CFD and analytical) for long term storage of cryogens. Model advanced design concepts in the appropriate environment and scale. Spray Bar Axial Jet Zero Boil-Off Provide IV&V for the Prime Contractor's design concept under the full range of mission/environmental conditions (including off-nominal). Method will be to develop parallel models (using different codes) and evaluate strengths and weaknesses of each approach. Fluent, CFX, Flow-3D, NCC, CAT, SINDA/FLUINT, GFSSP Compare and anchor models to existing ground and flight data. Identify additional tests - MHTB, Mass Gauge

Researchers from Combustion Branch:

Jeffrey P. Moder
Anthony C. Iannetti