Radiative pyrolysis of a double-base propellant

The overall objective of this research is to augment our understanding of the thermophysical and chemical processes involved in the electro-thermal- chemical ignition of solid propellants. To understand the role of radiation, a double-base propellant known as JA2 was considered. A variety of measurements were conducted to analyze the gas-phase products generated. These include gas-phase temperature and pressure, gas-phase species, and estimation of species relative mole fractions. To further elucidate the radiative pyrolysis of JA2, confined rapid thermolysis of the propellant was also conducted. Results suggest that the instantaneous value of the transient absorbed radiant heat flux is quite high (∼10³ MW/m²), and that the contribution from the UV wavelength region dominates over the visible and IR regions. Radiative pyrolysis of JA2 within a constant-volume chamber suggests that, for moderate plasma energy levels, radiative heating alone may produce a high temperature and pressure of the products evolved into the gas-phase region, but cannot ignite the propellant. Additionally, species produced during radiative pyrolysis of JA2 are found to be different from that generated during standard thermolysis experiments. It is possible that the UV radiation from the ETC plasma photolyzes the oxidizers (such as NO₂), and thus reduces the chemical activity of decomposition products, prohibiting ignition of JA2.