Study of the gas-phase chemistry of RDX - Experiments and modeling

Abstract

The objectives of this work were to identify the species produced during the CO2 laser-induced decomposition of 1,3,5-trinitrohexahydro-s-triazine (RDX) and to obtain species profiles in the gas-phase during laser-assisted combustion for comparison to a one-dimensional model of the flame. In the experiments, a microprobe/mass spectrometer system was used to measure quantitative gas-phase species profiles and a high-magnification video system was used to observe surface behavior and flame structure. Gas-phase species evolved from the surface and also inside a bubble were measured. The species identified at the surface were HCN, NO2, H2O, NO, CO, N2O, N2, and H2; no CO2 was found at the surface. Formaldehyde may have been present, but it could not be unambiguously identified. Species mole fractions measured at 1.0 atm and a heat flux of 400 W/cm were used as input to a one-dimensional model along with a temperature profile obtained from the literature for similar experimental conditions. In order to obtain reasonable agreement between the model and the experiments for stable species, RDX vapor had to be added to the initial species for the model calculations. However, even with this addition, the profiles for OH and NH did not match data available in the literature.