Validation of Ablation and Thermal Response Model for Three-Dimensional Multifunctional Ablator

A semi-empirical physics-based ablation and thermal response model was developed for the 3-Dimensional Multifunctional Ablative Thermal Protection System (3D-MAT) material. Model validation was achieved through comparison between computation and available data obtained in the arc-jet test series, which were conducted at NASA Ames Research Center from 2014 to 2020. The charring ablator simulations for arc-jet test models presented in this work were computed by the Two-Dimensional Implicit Thermal Response and Ablation (TITAN) code, and the Data-Parallel Line Relaxation Method (DPLR) code was used for arc-jet flow simulations to estimate the arc-jet stream total enthalpy and define the aerothermal boundary conditions over the test model surface for TITAN simulations. Because of low surface catalytic efficiency of 3D-MAT char, the exact surface heating could not be determined. Thus, three different types of boundary conditions, including 1) fully catalytic surface heating, 2) noncatalytic surface heating, and 3) surface temperature and recession, were used in the TITAN simulation for model validation. The predicted surface and in-depth temperature history for arc-jet test models were compared with pyrometer and thermocouple data, and the predicted test model surface recession and char depth were compared against the posttest measurements.