Ab initio simulations of thermodynamic and chemical properties of detonation product mixtures

Abstract

Thermodynamic and chemical properties of simple fluids N2, CO2, and H2 O and their binary and ternary mixtures have been studied using density functional theory simulations in a high pressure and high temperature regime. We show that N2 and binary mixtures with N2 follow an ideal behavior over a large temperature and pressure range. On the contrary, the water molecule is observed to dissociate as either pressure or temperature increases. Dramatic consequences are observed when water is mixed with carbon dioxide at extreme conditions. Indeed, a new molecule is formed, CO3 H2, and the thermodynamic behavior of the mixture strongly deviates from ideality. Chemistry occurring at extreme conditions is then discussed in the context of detonation product modeling. © 2009 American Institute of Physics.