Aluminum powder as an important high-energy additive in solid propellants, can significantly improve propellant specific impulse. However, the large amount of aluminum oxide particles produced during its combustion can easily cause nozzle deposition and two-phase flow losses, affect engine performance. Regarding the problem of the difficulty in accurately predicting the formation and evolution of alumina particles during the combustion of aluminum particle clouds, this paper constructs a numerical model that couples the Euler–Lagrange two-phase flow framework with the Population Balance Equation (PBE), and use the Taylor Expansion Matrix Method (TEMOM) to achieve efficient solving of PBE, thus achieving a quantitative prediction of the evolution of alumina particle size distribution. Numerical simulation of the jet combustion process of aluminum particles with different particle sizes of 200 nm, 400 nm, and 600 nm, analyzed the temperature structure of the flow field and the evolution pattern of alumina particles. The results show that smaller aluminum particles ignite earlier and burn more rapidly, as the particle size increases, the temperature peak moves downstream along the axis. The number density of alumina particles along the axial direction shows a distribution feature of first increasing and then decreasing, the geometric standard deviation of its volume eventually stabilizes at about 1.8–2.0,exhibits typical self-preserving distribution characteristics. The research results can provide a theoretical basis for optimizing the particle size of propellant aluminum powder and inhibiting engine deposits.

Ningning Sun, Bingfa Zhang, Ya Jiang. Multi-Scale Simulation of Al₂O₃ Particle Formation and Evolution during Aluminum Particle Group Combustion Using a Coupled CFD–PBE–TEMOM Model. Academic Journal of Engineering and Technology Science (2026), Vol. 9, Issue 3: 1-14. https://doi.org/10.25236/AJETS.2026.090301.

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