Comparison of Material Response Models for Low-Density Ablative Materials

The objective of this study is to investigate the differences and similarities between two commonly used material response (MR) models: 1dFIAT (Fully Implicit Ablation and Thermal response program) and ITRAC (Insulation Thermal Response and Ablation Code). Models of an OTB (Oxy-Acetylene Test Bed) are compared to each other and to experimental results to find the strengths, weaknesses, and limitations of each MR model. Two different surface thermochemistry programs were evaluated to create B’ tables for the models. PICA (Phenolic Impregnated Carbon Ablator) was used as a model ablative material and was evaluated at 3 different heat fluxes (250, 500, and 750 W/cm2) for 60 seconds. A sensitivity analysis was performed and machine learning was used to generate and predict boundary conditions. The ideal applications for each program and challenges associated with material response modeling are also discussed.