A Statistics-Based Material Property Analysis to Support Ablation Simulation UQ Efforts

Accurate characterization of Thermal Protection System (TPS) material properties is an important component in modeling and simulating the response of the material under heating. Unfortunately, for many common TPS materials, especially ablators, these material properties are not always well known and contribute a source of aleatory uncertainty to thermal simulations, impacting the safety and reliability of entry systems. Furthermore, eorts to capture these uncertainties have been hampered by a lack of suitable experimental data to establish proper input statistics, necessitating the use of ad-hoc methodologies to fabricate input PDFs. In this work, new ablator material property data from the Mars Science Laboratory (MSL) program is used to construct experimentally-based material property PDFs for use in non-deterministic ablation simulations. A standard UQ propagation, sensitivity analysis and uncertainty contributor breakdown analysis is performed using the revised input set in the anticipated MSL aerothermal environment. Lastly, a problem is formulated to quantitatively establish the relationship between errors in input statistics and errors in output quantities of interest.