Inverse Determination of Thermal Parameters of Solid Propellants for Mathematical Models in Cook-Off Simulations Using Small Sample Quantities

Understanding the sensitivity of ammunition to external mechanical and thermal stimuli is critical for the safe and effective design of solid propellants in barreled weapon systems. In high-rate-of-fire scenarios, accumulated thermal loading, especially within the barrel, can expose subsequent rounds to elevated temperatures, potentially triggering cook-off through hotspot ignition. Numerical simulations are instrumental in modeling these thermal effects and guiding the design process. State-of-the-art multiphase models can capture the interaction between solid propellants and the gaseous phase in the heating, ignition and combustion processes. However, the predictive accuracy of these models heavily depends on the proper parametrization of thermal transport phenomena within the energy equation. This study presents a simulation based inverse parameter identification methodology to estimate key thermal properties based on small-scale experiments. The resulting parameters can improve the fidelity of thermal simulations and inform future designs aimed at increasing the thermal insensitivity of ammunition systems.