Oscillations Characteristics of One-dimensional Detonation Waves in Non-Uniform Hydrogen-Air Mixture

The inhomogeneity of the medium in front of the waves has a significant effect on the propagation of gaseous detonation waves, but the interaction mechanism remains unclear. The two鄄step induction鄄exothermic reaction model is used to study the propagation characteristics of one鄄dimensional hydrogen / air detonation waves in a non鄄uniform medium, and the influence of perturbation wavelength on detonation waves under different oscillation modes is analyzed. The results show that as the perturbation frequency get closer to the inherent oscillation frequency of detonation waves, the inherent instability is more easily triggered, resulting in more irregular oscillations. There are two dominant mechanisms of detonation waves propagating in a non鄄uniform medium. Pressure oscillation of weakly unstable detonation waves are dominated by density perturbation, and the main frequency of detonation pressure oscillation is consistent with the perturbation frequency; the pressure oscillation of strong detonation waves are dominated by inherent instability, and the oscillation frequency is distributed in the low frequency region without obvious dominant frequency, where perturbation only enhances the oscillation amplitude. When the perturbation is applied, the detonation waves under atmospheric pressure and at high altitudes has the above oscillation characteristics, which further confirms the feasibility of regulating detonation waves by artificial perturbation. © 2023 China Ordnance Society. All rights reserved.