Enhancement of the DDT Process with Energetic Solid Particle

Abstract

In the pulse detonation engine development, it is believed that the presence of solid particles can rapidly accelerate the flame speed and facilitate a rapid transition to the detonation. In this study, numerical simulations are performed to investigate the dynamics of the deflagration-to-detonation transition (DDT) in the pulse detonation engines using aluminium particles. The DDT process and detonation wave propagation towards the unburnt hydrogen/air mixture containing aluminium particles are numerically studied using the Eulerian-Lagrangian approaches. The numerical results show that the aluminium particles not only shorten the DDT length but also reduced the DDT time. The improvement of the DDT process is primarily attributed to the heat released from the aluminium particle surface chemical reactions. The temperature associated with the DDT process is higher than the case of no energetic particle added, with an accompanying rise in the pressure. The more aluminium particles are added, the more heat is released in the combustion process, thereby, resulting in a faster DDT process. In essence, energetic particles contribute to the DDT process of successfully transiting to detonation waves for the (failure) cases, in which the fuel mixture can be either too lean or too rich.