This work investigates atomic recombination of gas species impinging on high-temperature materials used for thermal protection system of spacecraft entering Earth’s atmosphere. Heterogeneous catalysis models of pre-oxidized PM1000, an oxide dispersion-strengthened Ni-Cr superalloy, and silicon-carbide-coated (SiC-coated) carbon-fiber-reinforced SiC used on the European eXPErimental Re-entry Testbed (EXPERT) are fitted making use of recombination coefficients obtained experimentally from exposing these materials to highly dissociated nitrogen and oxygen flows in a plasma wind tunnel. These models are finite-rate catalytic models that consider associative adsorption, thermal desorption, and Langmuir–Hinshellwood and Eley–Rideal reactions. Recombination coefficients from different techniques are included to increase the variation of surface temperature and partial pressure of the sampling, which also increased the level of verification of the methods applied here. A pressure-dependent model for copper oxide at 320 K is also fitted, which is of special interest for investigations in ground facilities because it is commonly used as highly catalytic reference surface on plasma diagnostic probes. The materials investigated here present full surface coverage up to 1500 K at reentry relevant pressures, and the Langmuir–Hinshellwood mechanism is the dominant mechanism for a wide pressure and temperature range.

这项工作研究了撞击进入进入地球大气层的航天器热防护系统的高温材料的气体物种的原子复合。拟合了预氧化的PM1000，氧化物弥散强化的Ni-Cr超级合金和碳纤维增强的SiC涂层的碳纤维增强SiC的非均相催化模型利用通过将这些材料暴露于等离子体风洞中高度离解的氮和氧流中而实验获得的复合系数。这些模型是考虑了缔合吸附，热解吸以及Langmuir-Hinshellwood和Eley-Rideal反应的有限速率催化模型。包括来自不同技术的重组系数，以增加表面温度和采样分压的变化，这也增加了此处应用方法的验证水平。还拟合了一个压力依赖性的320 K氧化铜模型，该模型对于在地面设施中进行研究特别感兴趣，因为它通常用作等离子体诊断探针上的高催化参考表面。此处研究的材料在折返相关压力下的最大表面覆盖范围为1500 K，而Langmuir-Hinshellwood机理是在宽压力和温度范围内的主要机理。还拟合了一个压力依赖性的320 K氧化铜模型，该模型对于在地面设施中进行研究特别感兴趣，因为它通常用作等离子体诊断探针上的高催化参考表面。此处研究的材料在折返相关压力下的最大表面覆盖范围为1500 K，而Langmuir-Hinshellwood机理是在宽压力和温度范围内的主要机理。还拟合了一个压力依赖性的320 K氧化铜模型，该模型对于在地面设施中进行研究特别感兴趣，因为它通常用作等离子体诊断探针上的高催化参考表面。此处研究的材料在折返相关压力下的最大表面覆盖范围为1500 K，而Langmuir-Hinshellwood机理是在宽压力和温度范围内的主要机理。