Abstract:

Under hypersonic flow conditions， due to the strong high-temperature thermochemical non-equilibrium effect and various heterogeneous reactions occurring at the gas-solid interface， to achieve the aerothermal environment and material thermal response prediction with high accuracy becomes very difficult. In particular to the ablative Thermal Protection Material （TPM）， thermal blockage and gas blowing effect may be caused by the physical and chemical interactions between TPM interface and the non-equilibrium flow environment， significantly affecting the aerothermal environment and material thermal response. In this work， a multiscale coupling simulation framework is established for the TPM ablation process， which not only can achieve the TPM recession rate and the transient re-shaping process of vehicles based on the thermochemical interfacial reactive model， but also is capable to capture the ablation generation development at the interface and its effect on the aero-thermal/-dynamics environments. Firstly， the establishment of the multiscale coupling simulation framework is described with details， followed by a benchmarking validation using a blunt body with Phenolic Resin （PR） as TPM. The results of the calculated ablation recession rate and the transient aerothermal environment are compared with literature to demonstrate the methodology validity. Such a multiscale coupling simulation method for TPM ablation based on the thermochemical interfacial reactive model is not only suitable for the PR material application， but can also be extended to other typical aerothermal environment prediction， which is of great help predicting hypersonic aerothermodynamic characteristics and improving the understanding of various TPM/non-equilibrium flow interfacial phenomena.

Key words: thermal protection materials, gas-solid interface, multiscale coupling simulation, reactive molecular dynamics, ablation