Thermal oxidation kinetic simulation of ignition and combustion of B–Mg–Al ternary metal alloy particles in alternating atmosphere

Abstract

Aiming at the demand for improving the heat release performance of solid propellants for high energy and complex practical application scenarios, the B–Mg–Al ternary alloy is proposed as a metal fuel additive. Based on the unique phase distribution of B–Mg–Al ternary metal alloy and the existing theory of ignition and combustion of metal particles, the kinetic simulation of ignition and combustion of B–Mg–Al ternary metal alloy particles in complex alternating atmosphere is carried out by combining with the virtual alternating atmosphere environment. The model calculates the combustion time t_c of 10 μm B–Mg–Al alloy particles in H₂O(g), H₂O(g)/Air alternating mode, and Air to be 3.50 ms, 3.98 ms, and 4.60 ms, respectively, and the comparative errors with the experimental measurement of combustion time are kept around 5%, which verifies the reliability of the model results. The simulation study shows that the order of thermal oxidation reaction and the order of combustion of the monomolecular group elements of B–Mg–Al ternary alloy particles are Mg, Al, and B, which to some extent indicates that the addition of Mg and Al has the potential to improve the ignition and combustion performance of B. In addition, there are obvious differences in the ignition and combustion performance and heat transfer performance of the alloy particles under H₂O(g) and that of Air with the same concentration, which leads to significant instability in both ignition and combustion processes at variable medium.