Acquisition System Testing with Superfluid Helium

Abstract

In support of NASA’s Superfluid Helium On-Orbit Transfer (SHOOT) Flight Experiment, two pumping approaches are being evaluated. NASA-GSFC is conducting tests on the thermomechanical (TM) pump while NASA-ARC is sponsoring tests on a centrifugal pump at the NBS Cryogenic Laboratory. For either of these approaches, a common concern is the method that should be employed for fluid acquisition. While technology is available for design, fabrication, and operation of fluid acquisition systems with conventional fluids, performance with superfluid helium (SFHe) is uncertain. As a result, Martin Marietta joined with NASA to investigate the use of capillary acquisition systems. Assurance is needed that the devices will work with superfluid helium under an adverse 10−4g operational environment. Minus one-g outflow tests were conducted with SFHe in conjunction with the TM pump set-up in the Cryogenic Laboratories at GSFC. Both fine mesh screen and porous sponge systems were tested. A screen acquisition device was also tested with the low-NPSH centrifugal pump. Results to date show that the screen and sponge are capable of supplying SFHe to the TM pump inlet against a one-g head up to four cm which is more than sufficient for the SHOOT application. Results with the sponge are reproducible while those with the screen cannot always be repeated. Further tests to characterize these systems are required.KeywordsCentrifugal PumpAcquisition DeviceSuperfluid HeliumPump InletCryogenic EngineerThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.