Competing effects of surface catalysis and ablation in hypersonic reentry aerothermodynamic environment

• DOI: 10.1016/j.cja.2021.11.025
• Publication Date: 2021-12-02T07:35:40Z
• Authors: Zhiliang CUI; Jin ZHAO; Guice YAO; Jun ZHANG; Zhihui LI; Zhigong TANG; WEN Dongsheng
• Keywords: Hypersonic flight; Sticking coefficient; Aerodynamic heating; Atmospheric temperature range

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