Numerical prediction, flight verification, and targeted regulation of multiscale thermal effects in thermal protection structures

<p indent="0mm">Composite materials and complex structures are integral to the thermal protection systems of near-space high-speed vehicles, exhibiting macro/microscale thermal effects. These multiscale effects introduce prediction biases in heat transfer characteristics of materials/structures, complicating the evaluation of thermal protection performance. This paper introduces the MMM–CVFVM cross-scale heat transfer prediction method to address these challenges. By integrating a microstructure intelligent reconstruction algorithm, the method effectively predicts multiscale thermal effects in composite materials. The prediction model has been validated through flight experiments with space vehicle models. Using multiscale analysis of directional energy transport, a new ceramic lattice superstructure for thermal protection was designed. Supported by numerical simulations and ground and flight experiments, this design achieves directional weight reduction and temperature control. The multiscale thermal effect prediction model established in this paper provides refined evaluation tools and design paradigms for thermal protection systems. It provides crucial theoretical and technical support for advancing next-generation near-space high-speed vehicles in China.