Thermophysical Property Characterization of Decomposing Aerospace Materials

i3 proposes to develop and implement a new time-efficient technique for generating statistically-based material response models that predict the decomposition process (pyrolisizing /charring) that thermal protection system materials undergo when exposed to severe aerothermal heating environments.The proposed material response design process integrates the use of novel test and evaluation (T&E) methodologies and facilities coupled to new modeling and simulation approaches.The resulting combination of novel testing and Modeling and Simulation (M&S) will enable the ability to develop high fidelity thermochemical decomposition models to support transient aerothermal analysis and system design. This process emphasizes the importance of measuring, recording, and predicting transient material behavior over the entire range of flight relevant environments.Ground testing will include the use of the AFRL Laser Hardened Materials Evaluation Laboratory (LHMEL) facility, a 10 kilo-watt fiber laser, to generate flight representative heating.Transient, in-depth thermal and density responses will be recorded and provided as inputs into to novel M&S method to define kinetic decomposition coefficients for the Arrhenius Rate equation.Decomposition parameters including temperature dependent thermal conductivity and specific heat, pyrolysis gas enthalpy, and various kinetic decomposition constants will be derived iteratively, culminating in the successful demonstration of a cost and time efficient, accurate process for characterizing material decomposition.Approved for Public Release | 17-MDA-9219 (31 May 17)