Ignition and Combustion Characteristics of Aluminum Hydride-Based Kerosene Propellant

Aluminum hydride (AlH₃) is a promising candidate for enhancing the combustion performance of liquid fuels due to its high energy density and exceptional hydrogen storage capacity. This study investigated the ignition and combustion characteristics of μ-AlH₃ particles in kerosene droplets using TG-DSC analysis, high-speed imaging, laser ignition, and combustion product characterization, with comparisons to micron- and nano-aluminum powders. Results showed that the exothermic combustion of hydrogen released from AlH₃ decomposition lowered the primary oxidation temperature of aluminum, leading to more intense combustion with smaller ejected particles. The particle size of kerosene droplets containing AlH₃ rapidly decreases due to the escape of hydrogen. The heat released by the combustion of hydrogen significantly accelerates the combustion of droplets, and the fastest combustion rate is observed at a concentration of 1% AlH₃. The combustion products of kerosene droplets containing AlH₃ are smaller than those of kerosene droplets containing aluminum, indicating that their combustion efficiency is higher. A combustion model for AlH₃-based kerosene droplets was developed, demonstrating less than 10% error in predicting ignition delay and burning rates. These findings provide valuable insights for the application of AlH₃ in liquid fuels.