关键词: 烧蚀热防护, 内部热响应, 移动边界, 动网格, 压缩存储, 数值仿真

Abstract: The key technology of numerical simulation of internal thermal response of carbonized composite material with pyrolysis reaction was researched deeply. Charred layer pyrolysis surface original material model was applied and convection heat transfer between pyrolysis gas and charred layer was treated as heat source. The linear equations of three dimensional temperature field were built with finite element method under moving boundary condition. The temperature field and pyrolysis gas mass flux were calculated with Gauss Seidel iteration method. At the same time, the method of dealing with moving boundary and dynamic mesh generation of three dimensional ablation was researched and analyzed. Because the mesh need to be regenerated in every time step, numerical simulation of ablation thermal protection had high demand in data storage and calculation efficiency. This paper researched the main factors that affected the storage and calculation efficiency. The method of compression storage and solution was presented. It is demonstrated by calculation results that the method of dealing with moving boundary is correct and proper, the storage method has high efficiency and it can speed up convergence of temperature field calculation by keeping the conductance matrix and capacitance matrix positive definite symmetric.

Key words: Ablation thermal protection, Internal thermal response, Moving boundary, Dynamic mesh, Compression storage, Numerical simulation