Computing continuum-level explosive shock and detonation response over a wide pressure range from microstructural details
W. Lee Perry, Amanda L. Duque, Joseph T. Mang, David Culp
Abstract
This paper builds upon our previous work where we defined distinct physically-based parameters of the Scaled Uniform Reactive Flow (SURF) model of Shaw and Menikoff for heterogeneous high explosives (HE) reactive flow calculations. We call this Physically-Informed version of the model PiSURF, or πSURF. Here, we re-derived the model in a manner that resulted in a dependency on the fraction of the overall specific surface area (associated with the void space in a consolidated sample) that is ‘activated’ by a shock wave. This perspective is appealing and consistent with the mechanism of combustion in this class of materials at lower pressures. We apply the model to three case studies having slight perturbations in the nominal microstructure of the explosive PBX 9502, characterized by a void volume distribution in the 0.1 nm–10 µm void size range, over a wide pressure range (0.01–0.6 Mbar/1–60 GPa). We concluded that the model provided meaningful predictions that agreed with our intuitive expectations, qualitatively supported by experimental evidence, for the entire relevant pressure range in a manner consistent with a more generalized picture of combustion in heterogeneous materials. This approach takes a significant step forward towards the broader goal of a priori calculation of the hydrodynamic behavior of HE from measurable microstructural details.