Under hypersonic flow conditions,the complicated gas-graphene interactions including surface catalysis and surface ablation would occur concurrently and intervene together with the thermodynamic response induced by spacecraft reentry.In this work,the competing effects of sur-face heterogeneous catalytic recombination and ablation characteristics at elevated temperatures are investigated using the Reactive Molecular Dynamics(RMD)simulation method.A Gas-Surface Interaction(GSI)model is established to simulate the collisions of hyper-enthalpy atomic oxygen on graphene films in the temperature range of 500-2500 K.A critical temperature Tc around 900 K is identified to distinguish the graphene responses into two parts:at T＜Tc,the heteroge-neous surface catalysis dominates,while the surface ablation plays a leading role at T＞Tc.Con-tradicting to the traditional Arrhenius expression that the recombination coefficient increases with the increase of surface temperature,the value is found to be relatively uniform at T＜Tc but decli-nes sharply as the surface temperature increases further due to the competing ablation effect.The occurrence of surface ablation decreases the amounts of active sites on the graphene surface for oxy-gen adsorption,leading to reduced recombination coefficient from both Langmuir-Hinshelwood(L-H)and Eley-Rideal(E-R)mechanisms.It suggests that the traditional Computational Fluid Dynamics(CFD)simulation method,which relies on the Arrhenius-type catalysis model,would result in large discrepancies in predicting aerodynamic heat for carbon-based materials during reen-try into strong aerodynamic thermal environment.

Zhiliang CUI;Jin ZHAO;Guice YAO;Jun ZHANG;Zhihui Li;Zhigong TANG;Dongsheng WEN

School of Aeronautical Science and Engineering,Beihang University,Beijing,100083,China;China Aerodynamics Research and Development Center,Mianyang,China;Ningbo Institute of Technology-Beihang University,Ningbo,Zhejiang 315100,China

中国航空学报（英文版）

[1]Zhiliang CUI;Jin ZHAO;Guice YAO;Jun ZHANG;Zhihui Li;Zhigong TANG;Dongsheng WEN-.Competing effects of surface catalysis and ablation in hypersonic reentry aerothermodynamic environment)[J].中国航空学报（英文版）,2022(10):56-66

aerothermodynamic,tradicting,decli

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