Abstract:Due to their extremely low vapor pressure, low toxicity and high thermal stability, hypergolic ionic liquids are considered to be the most potentially green fuels to replace hydrazine and its derivatives as a new generation of propellant. A better understanding of hypergolic combustion and ignition process will promote the practical application of ionic liquids-based propellant systems. In this paper, recent advances in ignition and combustion mechanism of hypergolic ionic liquids are reviewed, which include three aspects: reaction routes and mechanism, ignition and combustion process, and theoretical prediction of hypergolicity. The reaction mechanism of dicyanamide anion and nitric acid, several stages and phenomena of ignition and combustion of hypergolic ionic liquid, several methods for predicting hypergolicity are introduced and summarized. The future researches should include the reaction mechanism of other anions, the development of green oxidizer to replace those toxic ones, normalization of the ignition device and method, and the accurate prediction of ignition performance.