Effects of oxidizers on the ignition and combustion characteristics of aluminum nanoparticles

Ignition and combustion of Aluminum nanoparticles (ANPs) under complex environments are of great significance for various propulsion systems. In this study, we investigated the oxidation process of ANPs in O₂, CO₂, H₂O, and their mixture atmospheres using reactive molecular dynamics. In the mixture atmospheres, ANPs experience a shorter ignition delay and parts of C and H atoms are involved in a new reaction named re-oxidation, where the nonbonded C and H inside ANPs detach from particle and re-bond with free O in the environment to produce extra CO and H₂O. It reduces C and H in unreactive diffusion and increases O in reactive diffusion. Additionally, it is found that the ignition delay time and reaction heat release can be adjusted to achieve the optimal performance of ANPs combustion by tailoring the contents of O₂, CO₂, and H₂O in the environment. Our works provide a theoretical basis for the precise regulation of ANPs energy release.