Fast estimation on the pressure of detonation products of cyclotetramethylene tetranitramine through molecular dynamics simulations

The equation of states (EOS) that correlates the pressure, volume and temperature (PVT) of detonation products is indispensable in the numerical modeling of blasting performances of energetic materials. Based on extensive molecular dynamics simulations on the mixtures of CO2, H2O, N2, CO and H2, which are the main components of detonation products of cyclotetramethylene tetranitramine (HMX), the relation of pressure with density, temperature and composition is derived in the range of 1.4–2.2 g/cm3 for density, 3000–4400 K for temperature and 8–40 GPa for pressure. The proposed EOS exhibits good general applicability under the studied conditions and reasonable agreement with the experimentally established Becker–Kistiakowsky–Wilson (BKW) equation. Although several approximations are applied in the computations and some deviations remains, it suggests an effective and feasible approach to establish the EOS for detonation products of energetic materials by means of molecular modeling.