Optimization effect and reaction mechanism of flake aluminum powder on the combustion performance of high-energy-density JP-10/PO composite fuel

JP-10 is a high-density hydrocarbon fuel known for its exceptional comprehensive properties and wide usage in scramjets and detonation engines. Previous research has successfully enhanced the ignition susceptibility and reduced the concentration of incomplete combustion products in JP-10 liquid fuel through the inclusion of diethyl ether (DEE) and propylene oxide (PO). However, it is worth mentioning that the density and bulk calorific value of hydrocarbons do not continuously increase with the addition of ring structures. As density rises, the fuel's low-temperature properties gradually deteriorate. Therefore, a novel solution is proposed: incorporating metal dust with a higher combustion calorific value to augment the energy density of the mixed fuel. This study explores the combustion and detonation properties of multiphase mixed fuels obtained by introducing flake aluminum powder to the JP-10/PO mixture. Furthermore, a multiphase chemical reaction kinetics mechanism for JP-10/PO/Al is developed. Adding aluminum powder accelerates the initial stages of JP-10/PO explosion, but it also intensifies incomplete combustion in the liquid phase mixed fuel under anaerobic conditions, causing significant smoke release. Additionally, the inclusion of aluminum powder prolongs the ignition delay time of the multiphase reaction system, intensifies the reaction, and increases the heat release rate. The coupling mechanism between aluminum powder and JP-10/PO primarily involves cross reactions with free radicals such as O, OH, and H. Moreover, the release of reaction heat from aluminum powder affects the gas-phase elementary reaction rate. Furthermore, as the aluminum content increases, the cracking or oxidation reactions of certain hydrocarbon macromolecules to produce smaller molecules become less sensitive to C₂H₄ and CH₂O components, while the oxidation reaction of aluminum particles weakens the original hydrocarbon macromolecule cracking or oxidation reaction.