Study on electrical ignition characteristics of ammonium dinitramide (ADN) -based liquid propellant droplet in nitrous oxide environment

Compared with hydrazine propellant, energetic ammonium dinitramide (ADN)-based liquid monopropellant has the advantages of high specific impulse, nontoxic, pollution-free, and easy storage. Moreover, ADN-based space engine has been applied in orbit, indicating a good application prospect. However, due to the use of a catalyst and catalyst preheating, it is impossible to realize the long life time of a thruster and the cold start of an engine in emergency. In this study, a new resistive ignition method was used to ignite ADN-based liquid propellant without a catalyst, and the electric ignition characteristics of ADN-based liquid propellant in nitrous oxide environment were studied. The results show that the resistive ignition method could be used to ignite ADN-based liquid propellant in nitrous oxide environment. The increase in voltage affected the decrease of ignition delay time, but slightly affected the combustion duration. With the increase in ambient pressure, the ignition duration of droplet gradually decreased. Voltage and ambient pressure slightly affected the energy consumption in nitrous oxide environment. Moreover, because the ignition delay time was much longer than the combustion duration, the ignition energy accounted for a high proportion of the energy consumed in the entire reaction process.