Improvements to steady-state combustion modeling of cyclotrimethylenetrinitramine

Many improvements have been made to models of cyclotrimethylenetrinitramine combustion in the past few years. The one-dimensional model presented in this paper models the solid, two-phase, and gas regions using complex kinetics and concentration- and temperature-dependent thermophysical properties. Calculated values agree well with experimentally determined burning rate sigma(p), melt layer thickness, surface temperature, and species concentration profiles. When including laser-assisted burning in the model, a dark zone appeared that was similar to that seen experimentally. With the laser-assisted case, the chemistry controlling the burning rate is significantly different from cases without the laser heat flux. Calculations show that the melt-layer thickness is determined primarily by the liquid thermal conductivity and the surface temperature is controlled by the vapor pressure correlation. All other model predictions are relatively insensitive to these parameters. The condensed-phase decomposition and evaporation/condensation submodel are the weakest areas of the model.