Thermal Performance of Spacecraft Wall Structures Using PCM-Embedded TPMS Designs

In this paper, the wall structure of the International Space Station (ISS) is used as a reference to investigate the thermal performance of spacecraft walls. The outermost surface is a 2mm thick 305-grade stainless steel, while the inner pressure shell is made of 50 mm thick 2219 aluminum-copper (Al-Cu) alloy. The majority structure sandwiched in between are 110 mm thick Kevlar ballistics protection layers. We propose new wall configurations in which the conventional Kevlar layer is replaced with a triply periodic minimal surface (TPMS) structure embedded with phase change material (PCM). The thermal performance of these novel designs is compared with that of the traditional wall configuration. Numerical analyses are performed on TPMS systems of identical dimension, including Gyroid, Schwarz, Diamond, and Neovius aluminum structures. Each system is uniformly filled with the organic phase change material RT35HC. A constant heat flux of 1361 W/m² (Solar radiation) is applied at the outer surface, while a constant ambient temperature of 298.15 K is maintained at the inner pressure shell wall. The temperature of 370 K at the outermost surface is designated as the cutoff temperature. The thermal performance of both the conventional and proposed wall configurations will be evaluated and compared through numerical simulations.