Arrhenius rate chemistry-informed inter-phase source terms (ARCIIST)

Currently, in macro-scale hydrocodes designed to simulate explosive material undergoing shock-induced ignition, the state of the art is to use one of numerous reaction burn rate models. These burn models are designed to estimate the bulk chemical reaction rate. Unfortunately, these burn rate models are largely based on empirical data and must be recalibrated for every new material being simulated. We propose that the use of Arrhenius Rate Chemistry-Informed Interphase Source Terms (ARCIIST) in place of empirically derived burn models will improve the accuracy for these computational codes. A reacting chemistry model of this form was developed for the cyclic nitramine RDX by the Naval Research Laboratory (NRL). Initial implementation of ARCIIST has been conducted using the Air Force Research Laboratory’s (AFRL) MPEXS multi-phase continuum hydrocode. In its present form, the bulk reaction rate is based on the destruction rate of RDX from NRL’s chemistry model. Early results using ARCIIST show promise in capturing deflagration to detonation features more accurately in continuum hydrocodes than what was previously achieved using empirically derived burn models.