Heat transfer mechanism of the C/SiC ceramics pyramidal lattice composites

摘要

An innovative design of pyramidal lattice composites with high temperature C/SiC ceramics as constituent has been proposed for the purpose of thermal protection system design. A sample with dimensions of 230 × 130 × 20 mm was firstly fabricated by interweaving and chemical vapor infiltration (CVI) method. Heat transfer mechanism of C/SiC lattice has been discovered to explore the optimal design of its excellent thermal protective properties. Optimal geometry parameter selection criterion has been proposed to balance the heat insulation and mechanical properties including stiffness and yield failure surface. And the critical surface emissivity was found for the dominant heat transfer mechanism transition from thermal conduction to thermal cavity radiation in the lattice. Simultaneously, the maximum temperature location transferred from the location of rod end to the center of panel. Filling insulation materials and surface modification to change the surface emissivity has been proved to be a significant way to improve the thermal protective properties. This novel design provides promising material candidate for thermal protection system.