Combustion promotion of aluminum-water propellant via ternary metastable intermolecular complexes

This paper addresses the issue of poor combustion performance of aluminum-water propellant by investigating the promotion mechanism of ternary metastable intermolecular complexes (MICs) on the performance of thermal decomposition, combustion, and agglomeration of aluminum-water propellant through a range of experimental techniques. An experimental study was firstly conducted to investigate the promotion of aluminum-water propellant combustion by Bi₂O₃ and polyvinylidene fluoride (PVDF). The findings indicate that Bi₂O₃ and PVDF augment the reactivity and reaction heat of aluminum powder, Bi₂O₃ was helpful for the combustion efficiency of the aluminum particles, and PVDF was more effective in inhibiting agglomeration and increasing the burning rate. Subsequently, an investigation was conducted to ascertain the promotional effect of Al/PVDF/Bi₂O₃ MICs on the combustion performance of aluminum-water propellant. The findings demonstrated that the activity of aluminum powder with ternary MICs was markedly enhanced, with a significant increase in the mass burning rate of the aluminum-water propellant (up to 70 %) and combustion efficiency (up to 13.5 %). Furthermore, the ternary MICs demonstrated superior inhibition of agglomeration compared to Al/Bi₂O₃ MICs. Finally, we preliminarily proposed the mechanism of action of MICs on combustion promotion of aluminum-water propellants. The mechanism of combustion promotion of PVDF and Bi₂O₃ on aluminum-water propellants is not simply the superposition of two mechanisms, but plays a role of mutual promotion, and better performance enhancement of combustion. In conclusion, the results of this study demonstrate that Al/PVDF/Bi₂O₃ MICs can markedly improve the combustion performance of aluminum-water propellants. The findings of this study, along with the experimental data and insights gained, can inform the development of advanced aluminum-water propellants for a range of propulsion and energy applications.