Designing Thermal Shield with Choice of Structure Parameters of Composite Based on Carbon Aerogel

Thermal protection of spacecraft experiences significant thermal loads and requires optimal designing, in terms of both technological and mass characteristics. Carbon aerogels are great interest for development of light high-temperature thermal insulation materials. Introducing them into the structure of composites enables reducing the radiative component of thermal conductivity at high temperatures due to the high extinction coefficient of carbon aerogels in the infrared range. As reinforcing fillers in such materials, highly porous cellular materials can be used, which give the composite sufficient mechanical strength. The physical properties of composites depend strongly on the microstructure of the reinforcing fillers. Therefore, multilayer thermal shield can be designed with choosing, along with the layer thicknesses, the material structure parameters that are optimal for the specific operating conditions of the spacecraft under development. The article presents an algorithm for optimally designing multilayer thermal insulation based on a carbon cellular material filled with aerogel subject to the dependence of the thermophysical properties on the microstructure of the cellular material. Practical application is illustrated with a problem of designing a three-layer thermal shield for a solar probe.