Microscopic calculations of Hugoniot curves of neat TATB and of its detonation products

TL;DR

This study uses atomistic simulations to calculate the Hugoniot curves of TATB and its detonation products, introducing a modified sampling method and analyzing the effects of solid phase inclusion on chemical equilibrium.

Contribution

It adapts the SCA method for Monte Carlo simulations and incorporates solid phase effects into the equilibrium calculations for detonation products.

Findings

Potential by Rai is insufficient for accurate Hugoniot prediction

Explicit solid phase modeling alters chemical equilibrium

Modified sampling method improves simulation accuracy

Abstract

We compute the Hugoniot curves of both neat TATB and its detonation products mixture using atomistic simulation tools. To compute the Hugoniot states, we adapted our "Sampling Constraints in Average" (SCA) method (Maillet et al., Applied Math. Research eXpress 2008, 2009) to Monte-Carlo simulations. For neat TATB, we show that the potential proposed by Rai (Rai et al., J. Chem. Phys. 129, 2008) is not accurate enough to predict the Hugoniot curve and requires some optimization of its parameters. Concerning detonation products, thermodynamic properties at chemical equilibrium are computed using a specific RxMC method (Bourasseau et al., Phys. Chem. Chem. Phys. 13, 2011) taking into account the presence of carbon clusters in the fluid mixture. We show that this explicit description of the solid phase immersed in the fluid phase modifies the chemical equilibrium.