A reactive flow simulation for the anisotropic ignition of an explosive crystal using adaptive mesh refinement

Abstract

In this study, we consider the anisotropic or direction-dependent ignition of single crystal pentaerythritol tetranitrate (PETN). Previous experiments have shown that the anisotropic ignition of PETN is induced by the crystal orientation and micro-structural features at the molecular scale. Numerical models have taken the standard approach of considering only the isotropic ignition via ignition and the growth process, which assume a perfect isotropy or orientation independence for the ignition of an explosive crystal. Based on our previously announced anisotropic concept, which depends on strain and the strain rate, we developed an adaptive mesh refinement technique to carry out three-dimensional simulations of the anisotropic ignition of a PETN crystal subjected to directional shock loadings.

Shock-Induced Anisotropic Metal Combustion

“…For a perfect spherical nanoparticle, surface reaction is always treated as an isotropic process with a moving reaction front. In theory, it can be further reduced to a one-dimensional problem despite particle size and surface morphology. − This approximation underpins numerous experiments, − theories, , and simulations. − However, the existence of energy, force, or reactant gradient could lead to the reaction enhancement of local sites and thereby induce anisotropic reactions. The effect of anisotropy depends on the reaction area and loading intensity, but the detailed mechanism remains unclear. , …”