Calibrating Physically-Informed Reactive Flow Model (πSURF) for PBX 9501

PBX 9501 has military and industrial applications due to its performance and sensitivity; its microstructure influences these properties through void collapse generating hot-spots. Scaled Uniform Reactive Flow (SURF) model is one method that describes hot-spot generation via void collapse. However, SURF description of GapStick Tests (GSTs) underpredicts the velocity of the pressure wave at large gap thicknesses. In this work, we hypothesize that the physically-informed SURF (πSURF) reactive flow model with its tabular burn rate can better describe experimental results compared to the analytical SURF model. πSURF burn rate table were increased around ~8 GPa and decreased below ~6 GPa resulting in velocity thickness effect curves more similar to experimental GST compared to SURF. πSURF is a powerful tool due to the ability to manipulate the non-analytically burn rate compared to other analytical reactive flow models (ARFMs). Additionally, πSURF is a physically-informed permitting one to calculate perturbation to the burn rate table based on changes in void volume distribution (VVD). As a result, πSURF is able to describe a range of experimental conditions by straightforwardly modifying the burn rate table and VVD influence on the rate, both improvements over ARFMs.