NASA EPSCoR: Multi-scale Data-driven Modeling of Radiative Transport Through Thermal Protection Systems

Multi-scale data-driven modeling of radiative transport through thermal protection systems Science-I: Savio Poovathingal, University of Kentucky NASA Partners: Ames Research Center, Johnson Space Center, Langley Research Center, Space Technology Mission Directorate ABSTRACT The NASA Kentucky EPSCoR Program’s mission is to enhance research and intellectual capacity of the state’s universities and colleges through strategic investments in NASA- priority research areas and to increase researcher competitiveness for non-EPSCoR NASA funding. With this motivation, and entry, descent, and landing (EDL) technologies being a key NASA priority, we propose to partner with three NASA centers to fundamentally transform the current state-of-the-art approach in modeling degradation and failure of thermal protection system (TPS) materials used on space capsules. Specifically, we aim to improve understanding of radiative heating of TPS materials by investigating the penetration of shock-layer and wake flow radiative signatures into the material, its coupling with other thermochemical processes, and the potential degradation and failure of the TPS material. These advancements will benefit the New Frontiers Dragonfly mission, and missions under development such as the Mars Sample Return (MSR), Venus Entry, and potential Discovery class missions to the gas and ice giants. It will also aid the analysis of MEDLI2 data from the Mars 2020 mission. The proposed research blends computational modeling tools with rigorous experimental validation and is aimed at reducing uncertainties associated with the effect of flow-field radiation on TPS materials. Advancements will be made to reveal insights on radiative physics at the microscale by explicitly accounting for the microstructure of the TPS material and simulating the transport of photons through the microstructure. The modeling will be validated through novel spectral measurements through small samples, where the microstructural details of the samples can be resolved. Investigation of radiative transfer (transport) through the entire TPS material will be performed through the expansion of the current state-of-the-art material response solver developed at the University of Kentucky, the only U.S. University with such capability. The macroscale modeling through the entire TPS material will be performed in conjunction with a custom variant of Knowledge Distillation, a machine learning technique, to reduce errors and uncertainties associated with the underlying assumptions in the macroscale approach required for radiative transport modeling. The machine learning technique will be trained against the microscale data, which will contain all the relevant physics at the highest fidelity. Modeling efforts at the macroscale will be compared against innovative effective radiative conductivity measurements, which will precisely validate the energy transport mechanism in each mode of heating. Finally, custom-designed experiments will be performed in the Hypersonic Materials Environmental Test System (HYMETS) arc-jet facility at NASA Langley Research Center (LaRC) to demonstrate the reliability of the models and tools developed in this research effort. The modeling approach, coupled with the unique experiments is the first-of-its-kind collaborative effort, with the goal of creating an entirely new modeling paradigm for the design of TPS materials. i