Insights from High-Order Accurate Mesoscale Simulations of Shocked Energetic Materials

Predictive modeling of the sensitivity and performance of energetic materials (EM) hinges on the accuracy of the mesoscale simulations. The thermomechanical phenomena like hotspots, shear bands, chemical reactions etc. used to characterize the sensitivity of EMs occur in the microstructure. QoIs from the mesoscale simulations are used to develop closure models to simulate the macroscale response of EMs. Therefore, to predict the macroscale response of EMs, the mesoscale dynamics must be captured accurately. The majority of numerical schemes used for computational studies aimed at predicting the sensitivity of EMs are at best nominally 2^nd order accurate and require well-resolved simulations to obtain grid independent solutions. In this work, we employ a 5^th order accurate scheme for the mesoscale simulations of energetic materials. The levelset method is used to delineate interfaces in a sharp manner and a Riemann solver is employed across the interface to maintain high order accuracy at the sharp interface. This high order technique provides exceptional resolution of the interfacial thermomechanical dynamics at the mesoscale and offers improved accuracy of the mesoscale simulations. Unprecedented resolution of the interfacial and localization (shocks, interfaces, reaction fronts, shear bands) dynamics is revealed. This work also evaluates the balance between computational cost and accuracy of the solutions obtained with high-order accuracy methods and allows for the assessment of the accuracy of state-of-the-art numerical solutions of shock interactions with heterogeneous energetic materials.