2020-07-292020-07-292020-07-31ICES_2020_317https://hdl.handle.net/2346/86401Jeff Diebold, Advanced Cooling Technologies, USACalin Tarau, Advanced Cooling Technologies, USAAndrew Lutz, Advanced Cooling Technologies, USASrujan K. Rokkam, Advanced Cooling Technologies, USAThe proceedings for the 2020 International Conference on Environmental Systems were published from July 31, 2020. The technical papers were not presented in person due to the inability to hold the event as scheduled in Lisbon, Portugal because of the COVID-19 global pandemic.Radiators for manned spacecraft, satellites, planetary rovers and unmanned spacecraft are typically sized for the highest power at the hottest sink conditions, so they are oversized most of the time. In order to address the need for light-weight and efficient radiators capable of a significant thermal turndown ratio, Advanced Cooling Technologies, Inc. (ACT) has developed a novel vapor-pressure-driven variable-view-factor and deployable radiator that passively operates with variable geometry (i.e., view factor). The device, utilizes two-phase heat transfer and novel geometric features that passively (and reversibly) adjusts the view factor in response to internal pressure in the radiator. This paper extends previous 2D structural modeling to three dimensions. A set of important geometric variables are identified and their influence on the view factor is parametrically investigated. In addition, a thermal model of the variable-view-factor two-phase radiator is introduced and used to demonstrate the thermal control capabilities of the concept. This work has been performed under NASA Small Business Innovation Research (SBIR) Phase I contract 80NSSC18P2187 and Phase II contract 80NSSC19C0209.application/pdfengVariable-view-factorTwo-phaseRadiatorPassive thermal controlPresentation