2018-07-072018-07-072018-07-08ICES_2018_192http://hdl.handle.net/2346/74161Michael Izenson, Creare LLCAmelia Servi, Creare LLCScott Phillips, Creare LLCSheldon Stokes, Creare LLCColin Campbell, NASA Lyndon B. Johnson Space CenterICES402: Extravehicular Activity: PLSS SystemsThe 48th International Conference on Environmental Systems was held in Albuquerque, New Mexico, USA on 08 July 2018 through 12 July 2018.Space suits for future exploration missions will have multi-mission goals with new and challenging requirements for the portable life support system (PLSS). In particular, the space suit ventilation loop requires cooling and flow measurement components that must meet specifications that go well beyond the capabilities of the components used for the existing Extravehicular Mobility Unit. The flow meter must provide high measurement accuracy over a wide flow range, compatibility with pure oxygen, low pressure losses, and very compact size. The heat exchanger that cools the ventilation loop must be built from materials that are compatible with the liquid cooling loop, and it must provide efficient gas cooling in a small package across conditions ranging from normal suit pressure to elevated pressure. This paper describes the development of a novel device that combines the flow measurement and cooling functions in a single, compact flow meter / heat exchanger (FMHX). We have developed design methods that enable us to assess trade-offs, optimize performance, and specify the design of an FMHX that meets the requirements and constraints for operation in future PLSSs. We used computational fluid dynamics analysis to validate the pressure drop and heat transfer characteristics of the FMHX design. Data from tests of a proof-of-concept FMHX show that the system meets all design requirements. We used the results from these tests to refine the design parameters and predict performance of an optimized, prototype FMHX.engspace suit life support systemsventilation loop flow meterventilation loop heat exchangerPresentation