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.