Performance Testing and Modeling of a Scaled Fusible Heat Sink Test Article for Exploration Vehicles

A water based fusible heat sink is envisioned for use in several future human space vehicles ranging from a deep space habitable airlock to lunar rovers. This radiator concept has the potential to enable active thermal control systems with a single benign working fluid (such as propylene glycol water) as dynamic loading is buffered by the heat capacity of the integrated water layer. This paper presents the results of evaluations of a scaled test article which includes integrated coolant tubes through the radiator’s water reservoir. This testing was completed to validate analysis results and provide insight into freeze direction and control given the enclosure volume’s unique geometry and internal features. The coolant flows through the radiator in two tube bank layers. The first layer is contained within the water volume near the heat rejection interface, i.e. the radiating surface, and the second layer is submerged within the entrained water volume. The inlet temperature and flow rates of each layer can be controlled independently to better match the thermal performance expected in the full scale radiator. Results indicate that a predictable freeze direction can be obtained repeatedly and the associated water ice spike formation can be tolerated by a flexible enclosure. Implications for the next iteration of full scale hardware design are also discussed.