Effects of inlet total pressure on the formation and propagation characteristics of n-decane two-phase rotating detonation waves

Abstract

In this paper, three-dimensional numerical simulations are carried out to study the influence of inlet total pressure (such as 1 MPa, 1.5 MPa and 2 MPa) on the two-phase rotating detonation wave behavior. The flow field characteristics, the formation mechanism and propagation parameters of two-phase rotating detonation wave are discussed in detail. The simulation results show that the inlet total pressure has a significant impact on the two-phase rotating detonation wave in the scope of our study. Specifically, it is found that n-decane droplets are not completely consumed around the detonation wave, the escaping droplets are still evaporated and deflagrated behind the detonation wave. The increasing total pressure contributes to droplets evaporation. In addition, the generation of hot spots is a crucial factor in the detonation formation process. The shock wave induction and pressure wave accumulation are two mechanisms for it. As the total pressure increases, chaotic instability is observed before the stable stage, including the quenching, re-ignition and re-orientation, which is responsible for the variation of the propagation mode and direction of the rotating detonation waves. Moreover, in our study, with the increasing of total pressure, the intensity and stability of the detonation waves both increase, while the variation of detonation velocity is not sensitive. Our results can provide useful guidance for the research of two-phase rotating detonation engines.