Pore scale visualization of thermal-fluid-structural evolution in the ablation of carbon/carbon composites

Understanding the complex thermal and physicochemical mechanisms of an ablated structure is fundamental for the accurate design of highly efficient thermal protection systems. This study proposed a pore-scale comprehensive model combining the lattice Boltzmann and volume fraction methods to couple the heat and mass transfer, flow, carbon interphase and ablation reaction in the ablation of carbon/carbon (C/C) composites. The influences of aerodynamic heat, pressure gradient, and kinematic viscosity on the thermal-fluid-structural evolution in the ablation of C/C composite structure were investigated. The results revealed that the velocity and structure morphology evolution rate in the C/C composite structure increased with an increase in aerodynamic heat. Further, the competitive relationship between the aerodynamic heat and convective heat transfer caused by the structural morphology evolution was identified. Moreover, the velocity and structural morphology evolution rate in the C/C composite structure decreased with an increase in the pressure gradient and kinematic viscosity. The findings of this study can be used as a guide for the design of C/C composite thermal protection systems.