Shape Memory Alloys for Regulating TCS in Space (SMARTS): Validated Multiphysical Modeling and Design Optimization of Morphing Composite Radiators



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51st International Conference on Environmental Systems


Future human spaceflight missions are expected to require increased turndowns in the amount of heat rejected by thermal control systems as they adjust to variations in heat loads and the surrounding thermal environment to maintain crew cabin temperatures at a hospitable level. Current radiator systems can achieve a turndown ratio of 3:1; however, future missions are expected to demand ratios exceeding 6:1. Variable heat rejection space radiators are posed to provide this capability. The morphing radiator concept presented here accomplishes this via shape change, alternatively exposing low and high emissivity surfaces to the environment as passively thermally driven by shape memory alloys. Shape memory alloys are unique materials that use a thermally induced solid-solid phase transformation to generate strain and then fully recover it. This work covers the development and implementation of a modeling tool to simulate the morphing radiator behavior with ultimate application as a design tool. The model incorporates a multiphysics scheme to couple the thermal and geometric response of the radiator, which is required to capture radiation dependence on view factor. The fully developed model is then used to optimize radiator composite layup, SMA properties and number of wires to achieve full closure. The composite performance is further investigated to assess the optimal ply orientations through the use of black box surrogate modeling techniques such as efficient global optimization. This methodology efficiently searches through the design space for the computationally expensive finite element model. Full closure of the morphing radiator is essential to maximize turndown during cycling within operational temperatures of the thermal control system, and thus closed (cold state) aperture angle represents the primary objective of a design of experiments. Design study results shown provide a range of desirable shape memory alloy properties and wire quantity, which define the targets for upcoming prototyping and demonstration efforts.


Sean Nevin, Texas A&M University, US
Joseph El-Ashkar, Texas A&M University, US
Collette Gillaspie, Texas A&M University, US
Darren Hartl, Texas A&M University, US
ICES103: Thermal and Environmental Control of Exploration Vehicles and Habitats
The 51st International Conference on Environmental Systems was held in Saint Paul, Minnesota, US, on 10 July 2022 through 14 July 2022.


shape memory alloys, radiators, thermal control, spacecraft, multiphysics, optimization