Predictive model for the ignition and combustion behaviors of micron-sized aluminum particles in a water vapor environment

The ignition and combustion behaviors of single-particle aluminum in a water vapor environment are among the most important basic research aspects of metal fuels and solid propulsion technologies. In this paper, the ignition and combustion behaviors of aluminum particles in a water vapor environment were modeled based on a traditional aluminum particle ignition model and the finite difference method. In addition, a metal single-particle ignition combustion test system was used to carry out relevant validation experiments. The validation results showed that the average error of the model remained within 10%. In addition, an initial oxide layer fusion module was established in conjunction with the results of a material mechanics study of Al/Al₂O₃. Moreover, the model was used to calculate the ignition behavioral parameters (ignition delay time and ignition temperature) of the aluminum particles under different initial parameters. Finally, an intrinsic mechanism model was created to evaluate the influences of the relevant parameters on the ignition behaviors of the aluminum particles. The model results showed that the initial oxide layer ruptured during the aluminum melting stage, the phase transition stress was the main factor leading to oxide layer rupture, the ambient temperature had a great influence on the ignition temperature, and all four initial parameters were negatively correlated with the ignition delay time.