Spacecraft smart radiation device with variable emission and low absorption based on phase change material VO2

With the development of space technology, the miniaturisation of satellites has posed a challenge to thermal control technology. As an essential spacecraft thermal control technology, variable emission thermal control devices are important for reducing the load and size of spacecraft and adapting to the complex and changing thermal environment of space. In this paper, a vanadium dioxide (VO2)-based multilayer films structure for thermal control device is proposed and analyzed. The influence of the thicknesses of the films on the emission of the structure and the solar absorption has been systematically investigated. Two commonly used optical dielectric layers, SiO2 and Al2O3, are selected for the study. Besides, regardless of whether the intermediate medium is SiO2 or Al2O3, the emission regulation can reach 0.47, and the solar absorption is smaller than 0.38. Furthermore, the high emission at high temperature is more conducive to realizing when the intermediate medium is SiO2, while Al2O3 has more potential to maintain low emission at low temperature. In addition, through analyzing the distributions of the electric field and normalized power dissipation density, it is found that the absorption enhancement originates from the intrinsic loss of the medium. Furthermore, the proposed structure is robust to the angle of incidence and the polarization. This work will provide important theoretical guidance for the design of spacecraft smart radiation devices.