Fuel

Ignition of a composite aluminised propellant (AP-H1PB-A/) in stagnant hot air is analysed theoretically, based on solid phase and gas phase t1leories. According to solid phase theory, ignition is due to reaction of the propellant in the solid phase at elevated temperatures. One-dimensional transient solid phase energy equation is solved to obtain t1le surface temperature profile oft1le propellant. By gas phase theory, an exothermic gas phase: reaction, adjacent to the propellant surface, is considered responsible for the ignition. The changes in temperature and concentrations in tIle gas phase and the temperature profile b'~low tIle propellant surface during tIle pre-ignition induction period are considered. Equations of energy and concentrations of reactants have been solved to obtain tIle species concentration and temperature profiles in tIle gas phase. An experimental investigation of the ignition of AP-H1PB-AI propellant is also carried out in a shock tube under end-mount conditions. Pressure and temperature ranges were 6-16 bar and 1500-3000 K, respectively. A comparison of the experimental data with predicted results Shows that the ignition in an oxidizing atmosphere is by gas phase reaction, whereas in an inert atmosphere, solid pllase,reaction may h.e predomillaIlt, T Temperature t Time y Mole fractio