Exploring mechanism of phenomena of transverse acoustic oscillations of detonation combustion

Aim. We have gradually come to believe that recent progress in PDE (Pulse Detonation Engine) research has made it quite feasible to let missiles, UAVs and UCAVs to employ two-phase PDE. We now report the results of our exploratory study on methods of controlling detonation waves on a two-phase PDE model. In the full paper, we explain in some detail our exploration; in this abstract, we just add some concise remarks to the two topics of our explanation: (A) experimental method and setup; (B) experimental results and analysis. In topic A, Fig. 1 in the full paper shows the schematic of our experimental two phase PDE model, 60mm in inside diameter, which includes the well-known Shchelkin spiral. In topic B, a proof-of-principle experiment of a two-phase PDE was successfully carried out by using liquid C₈H₁₈/air mixture with low-energy system (total stored energy of 50 mJ) and then a new one-step detonation initiation method was developed. Also in topic B, experimental results, summarized in Figs. 2 and 3, show that the measured detonation wave pressure was very close to that of fully developed detonation. Again in topic B, Figs. 3 through 6 in the full paper show clearly the very important fact that transverse acoustic oscillations with its frequency range from 10 kHz to 12 kHz occur in detonation reaction zone, which has the characteristic scale of detonation tube inner diameter. Still in topic B, when band block filter of the band scope was carried out on a detonation time-pressure curve, detonation wave peak pressure decreased significantly, implying that the oscillations have an obvious effect on detonation characteristic parameters such as detonation peak pressure. Finally, in summary, based on the mechanism of transverse acoustic oscillations of detonation wave, a method has been presented here to control both detonation wave and deflagration to detonation transition (DDT) by suppressing or promoting transverse acoustic oscillations of detonation wave during DDT process and detonation wave sustained propagation.