催化效应对气动热环境影响的流动-传热耦合数值分析

鉴于高超声速飞行中高温气体效应带来的壁面催化反应可显著增加气动热载荷，在气动热环境与结构热响应的分析与预报中需充分考虑催化反应带来的影响。将简化原子复合催化模型和有限速率催化反应模型嵌入超高速流动-传热耦合分析模型中，建立超高速流动/催化反应/传热多场耦合分析模型。其中，通过高频等离子风洞的催化特性测试获得ZrB₂-SiC超高温陶瓷材料表面催化系数与温度的函数关系，对比分析耦合计算和非耦合计算、简化原子复合催化模型和有限速率催化反应模型对气动热环境的影响和适应性，结果表明材料表面催化特性对壁面总热流有重大影响。对于具有较高热导率材料的热响应，耦合传热分析能够有效避免非耦合计算带来的过度高估的结果，而有限速率催化反应模型可有效提高计算精度。在此基础之上，通过耦合传热分析，揭示了催化反应与壁面传热的内在关系，证明了在传热分析中考虑表面催化效应可提升结构热响应精度和防热系统精细化设计的能力。

Study on the influence of catalytic effect on the aerothermal environment by the flow-heat transfer coupling numerical analysis

In view of the high-temperature gas effect in the hypersonic flight, the wall catalytic reaction can significantly increase the aerodynamic thermal load. For the analysis and prediction of the aerodynamic thermal environment and structural thermal response, the influence of the catalytic reaction should be fully considered. In this paper, the simplified atomic recombination catalytic model and the finite-rate catalytic reaction model are embedded in the ultra-high-speed-flow heat-transfer coupling analysis model to establish a ultra-high-speed flow/catalytic reaction/heat transfer multi-field coupling analysis model. Among them, the surface catalytic coefficient of the ZrB₂-SiC ultra-high temperature ceramic material is obtained as a function of the temperature through the catalytic experiment of the high-frequency plasma wind tunnel. The coupled calculation and the uncoupled calculation, and the simplified atomic recombination catalytic model and the finite-rate catalytic reaction model are compared. It is found that the total heat flow of the wall depends on the surface catalytic properties of the material. For the thermal response of materials with higher thermal conductivity, the coupled heat transfer analysis can effectively avoid the uncoupled calculation zone. The finite-rate catalytic reaction model can improve the calculation accuracy to avoid over-estimation. On this basis, the intrinsic relationship between the catalytic reaction and the wall heat transfer is revealed by the coupled heat transfer analysis. It is proved that the surface catalytic effect should be considered in the heat transfer analysis to improve the thermal response accuracy of the structure to promote the design capabilities of the thermal protection system.