COMBUSTION MECHANISM OF ADN-BASED COMPOSITE PROPELLANT

摘要

Combustion characteristics of pelletized ammonium dinitramide (ADN) and ADN-based propellants have been studied. Micron-meter-sized particles of Al, Fe2O3, TiO2, NiO, Cu(OH)NO3, Cu and CuO, and nano-meter-sized Al (Alex) and CuO (nanoCuO) were employed as the additives for pelletized ADN. Only nanoCuO and Alex show the remarkable effects, so they are also added to ADN-based pro-pellant. The binder of ADN-based propellant is thermoplastic elastomer (TP), and three kinds of mixtures (TP:ADN = 30:70, 20:80 and 10:90 mass%) were prepared .The burning rates of pelletized ADN and ADN-based propellants were measured under the pressure range from 0.6 to 6.2 MPa, and the surface temperature profiles were obtained about ADN-based propellants. Nano-sized CuO enhanced the burning rate of pelletized ADN. Alex-incorporated ADN burned with flames even at 0.55 MPa under which pure ADN does not form the flame. Burning rate of non-additive ADN-based propellants has extremely high pressure dependency. In the case of TP/ADN (30:70), burning rate jump are found from the critical pressure approximately 3.2 MPa. The temperature profiles of TP/ADN (30:70) were measured, and the combustion structure was discussed. Both nanoCuO and Alex improved the burning rate characteristics, and the pressure exponents are 0.54 and 0.76 respectively.