Session: 04-09: SMA Enabled Smart Structures

Paper Number: 111116

111116 - Simulation of Shape Memory Alloy-Actuated Adaptive Thermal Control Systems in Space Environments 

Human crewmember survival is essential to establishing an indelible presence on the Moon. Thus, crewed areas of spacecraft must remain within delicate temperature limits for human survival. Thermal control system (TCS) architecture primarily relies upon radiative methods to reject excess heat. During hot phases, mechanically pumped fluid loops must transfer waste heat from internal spacecraft components to an external radiator. Factors restricting radiator capability are the provision of power and radiating surface area limitations. A morphing radiator concept uses the passively stimulated thermomechanical constitutive response of shape memory alloys (SMAs) to actuate a flexible radiator panel. Tuned to mission-specific requirements, SMA materials adjust the radiator view factor in response to heat rejection needs and the existing radiative environment. To evaluate the benefit of SMA-actuated thermal control, the operating envelope of a traditional flat panel radiator-based TCS is compared to the extended operating envelope of the morphing radiator-based TCS during a mission beyond low Earth orbit (LEO). Novel, multiphysics finite element models simulate both TCS designs. User subroutines model the hysteretic behavior of the SMA material, regulate the working fluid mass flow rate, and simulate a representative lunar mission via the inlet temperature of the radiator array. The performance of each design is quantified using a metric calculated as turndown (i.e., the ratio of the maximum to the minimum heat rejection rate). Both the divisor and dividend of turndown are collected during a partitioned thermomechanical analysis archetyping a mission. An additional metric assesses TCS efficacy: the minimum working fluid temperature over the mission, which governs the practicality of a single, non-toxic working fluid loop. Results from these two metrics for four unique mission contexts substantiate the claim that a morphing radiator-based, single-loop TCS will outperform a flat panel radiator-based, single-loop TCS during a mission beyond LEO.

Presenting Author: Collette Gillaspie Texas A&M University

Presenting Author Biography: Collette Gillaspie earned her Master of Science in Aerospace Engineering at Texas A&M University in August. Her research in the Multifunctional Materials and Aerospace Structures Optimization Laboratory centered around a morphing radiator for deep-space applications. In addition to adaptive thermal control system simulation, Collette harbors an excitement for additive manufacturing computational research. During the summer of 2022, Collette interned at Sandia National Laboratories in Albuquerque, New Mexico and supported the development of a distortion compensation algorithm for metal additive manufacturing. During the summer of 2023, Collette continued her work in additive manufacturing, specifically Rapid Plasma Deposition®, at Norsk Titanium in Hønefoss, Norway.