SBIR-STTR Award

As NASA prepares to make manned missions into deep space, the management of cryogenic fluids will become increasingly important. Cryogenic fluids such as liquefied hydrogen, oxygen, and methane are expected to be used for chemical and nuclear propulsion, fuel cells, life support systems, cooling, refrigeration, liquefaction, and In-Situ Resource Utilization. Transfer of stored cryogenic liquids from a supply tank to an empty tank will be an important procedure during which phase change will occur. In addition, temperature fluctuations during long term storage of cryogenic fluids can result in the vaporization of these liquids. In low gravity conditions, buoyancy forces will be insufficient to separate the vapors formed from the liquids and the presence of vapor in the liquid streams will interfere with combustion in engines, and pumps, resulting in equipment damage. In this Phase I SBIR project, we propose to demonstrate the feasibility of using a specially designed chamber to separate the vapor from the cryogenic liquid. This separator will use swirl to generate centripetal forces to force vapor out of the liquid into the central core of the vortex. The lighter vapor bubbles will separate from the cryogenic liquid to form a stable core in the center of the chamber surrounded by the liquid. The vapor can then be pumped from the system and collected for further use. The design will prevent the vaporous core from reaching the liquid exit. The liquid stream will flow out of the other end of the chamber where it can be stored or transferred. This approach is based on our previous separator designs for removing air from water under microgravity. The resulting technology has been tested under microgravity conditions. Based on those results the application of a similar design to cryogenic fluid management is predicted to succeed. Potential NASA Applications (Limit 1500 characters, approximately 150 words) Numerous NASA applications to be used for longterm space habitation and manned missions into deep space will require cryogenic fluids management. These include the storage and transfer of cryogenic fluids for chemical and nuclear based propulsors, life support systems formation and recovery of fluids generated in situ, etc. Longterm storage of cryogenic fluids may subject the stored fluids to boil off. Therefore, cryogenic phase separation is needed to protect pumps and equipment from bubbly flows in low gravity conditions. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words) The separation of vapor phases in cryogenic fluids is applicable in Magnetic Resonance Imaging equipment, superconductors, supercomputers and cryopreservation of biological samples liquefaction of natural gas and cryopreservation of pathology and biological samples. This technology could also be used in hospitals and medical research centers, as well as Department of Defense missile programs.

Cryogenic fluid management is critical for long term deep space manned missions. The nature of these missions will require long term storage of cryogenic liquids. Temperature fluctuations will result in some liquid vaporization and the formation of two-phase vapor-liquid mixtures, which would cause operational problems in pumping, transfer, and fueling systems. In low gravity conditions, vapor and liquid phases will not separate in distinct regions due to the lack of buoyancy forces, therefore a means of separating the two-phases is needed. In this proposal, we will pursue the development of the DynaSwirl® cryogenic separator demonstrated in Phase I, into a practical system that would operate in cryogenic liquid transfer high flow regimes. The design will be refined and optimized. The separator weight and the pressure drop across it will be minimized, a vapor capture system will be developed, and several prototype versions will be tested under a variety of conditions. To do so, the LN2 Cryogenic testing loop used in Phase I will be improved and upgraded with automation of valves’ control and data acquisition. The cryogenic tests will be conducted for times long enough to cover steady flow following the fill-out time and negligible effects of gravity on the separation will be demonstrated by conducting tests with different chamber orientations. The effects of the various geometrical dimensions of the separator components will be investigated and scale ups of the system to large exit diameters and high pressures will be considered. System level design study will be conducted to predict the behavior of the DynaSwirl® Cryogenic Phase Separator compared to other propellant management devices (PMD). A separator test unit for microgravity flight testing will be set up for future reduced gravity tests and a prototype of the separator for conditions of interest to NASA researchers will be delivered to NASA for testing with different cryogenics such as liquid O2 and CH4. Potential NASA Applications (Limit 1500 characters, approximately 150 words): Long-term space habitation and manned missions into deep space will require cryogenic fluids management, including the Human Landing System (HLS) for the Artemis Mission for lunar landings, future missions to Mars, storage and transfer of cryogenic fluids to be used in chemical and nuclear propulsors, life support systems, formation and recovery of fluids generated in situ. The presence of vapor in cryogenic liquids requires the ability to separate phases in low gravity conditions, which will be provided by the DynaSwirl®. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): The rapid and efficient removal of vapor in deep cooling systems is also a significant problem for hydrogen fuel storage and transfer, LNG infrastructure, medical imaging equipment, supercomputing facilities, superconductors, and cryopreservation of pathology and biological samples. The DoE, DOD missile programs, and medical and scientific facilities would also use the technology. Duration: 24