Stable detonation characteristics of premixed C₂H₄/O₂ gas in narrow gaps

Abstract

The detonation initiation and propagation characteristics of premixed gas in a confined channel are greatly influenced by some external factors, such as the channel size and the initial pressure. The influences of different gap height and initial pressure of stoichiometric C₂H₄/O₂ combustible premixed gas on the detonation characteristics were investigated using the self-made narrow gaps. The flame propagation processes were captured by the high-speed photography and the detonation trajectories were recorded by the soot-foil technology. The results show that the gap height is found to be proportional to $P_{0}^{ - 1.493}$ of the dividing lines, which are used to distinguish the three different detonation states. The detonation initiation process can be accelerated by either decreasing the gap height or increasing the initial pressure. Furthermore, the detonation velocity deficit is closely related to the gap height and the initial pressure, and the relation can be expressed as $d_{\text{V}} \propto H^{ - 0.8} P_{0}^{ - 0.5}$.