In this work, the combustion regularities of a high energetic double-base model propellant, based on nitrocellulose (NC) and nitroglycerin (NGC), with HMX were studied by examining combustion rate and temperature distribution parameters in combustion wave at pressure range 1-10 MPa. It was found that the influence of HMX mass content (particle size > 20μm) on combustion rate of base propellant has extreme nature with the lowest value at ~50% HMX content. It was established that during the combustion process of propellant sample with 50% HMX, intensive decomposition of NC and NGC takes place in the condense phase at temperature 50-70 K lower than the inflection temperature, obtained from the temperature distribution measurements, and the resulting intermediate combustion product gases make the dispersion of thermally stable molten HMX layer into gaseous zone. The higher heat effect due to more intensive chemical reactions was also observed in the first flame zone just above the combustion surface. Based on the experimental results, the condense phase combustion mechanism was proposed.
double-base propellant, HMX, combustion, temperature distribution