Design of high-performance thermal protection taking into consideration the highly porous cellular materials' microstructure

Highly porous cellular materials have extensive possibilities as part of multilayer heat-protective coatings under intense thermal loads. These materials can be used as thermal insulation layers or as reinforcing fillers in composite materials, providing them with the required mechanical and thermophysical properties. The thermophysical properties of Highly Porous Cellular Materials (thermal conductivity and heat capacity) depend on many factors: temperature, heating rate, material’s composition and structure, microstructural geometric characteristics, raw material properties (precursors), production technology features and operating conditions of materials (in vacuum, in air or in a gaseous medium). On one hand, this makes possible, during the optimization process of heat protective coatings, consisting of Highly Porous Cellular Materials, simultaneously solving the thickness of the layers and selecting parameters that characterize the microstructure of the material, to create materials with the desired properties. On the other hand, such a multifactorial nature complicates determining, modeling and predicting the properties of materials, and increases the spread of their values. Algorithms for optimizing multilayer thermal protective coatings, including layers of high-density coatings, should be resistant to errors in setting the initial data (thermal loads, thermophysical and optical properties of materials, structural parameters of materials). This paper is devoted to the study of the stability of the algorithm for the optimal design of a heat-protective coating using the projected Lagrangian method. The efficiency and stability of the algorithm is illustrated by solving the practical problem of designing a heat shield for the Interhelio-zond spacecraft. • A design methodology takes into consideration the microstructure of highly porous cellular materials to create materials with the desired thermophysical properties. • The effect of errors in setting the parameters of the material structure on the thermal conductivity of a highly porous cellular material is considered. • The efficiency and stability of the optimization procedure is confirmed by test problem solution.