Study on direct initiation process and initiation mechanism of acetylene/oxygen premixed gas detonation

Studying the process and mechanism of direct initiation of gas detonation is the basis for preventing serious gas explosion disasters and developing detonation propulsion power devices. This article utilizes a combustible gas combustion and explosion experimental system to achieve direct spherical acetylene/oxygen mixture detonation through a high-energy ignition system. The detonation velocity and flame structure evolution process in direct detonation were studied through schlieren images, and a critical detonation model was established to explain the direct detonation process. The critical detonation wave velocity for direct detonation was determined to be half of the CJ detonation velocity. Revealed the mechanism of detonation cell formation during the direct initiation process. The basic criterion for achieving direct initiation of spherical detonation has been obtained: to achieve direct detonation, when the overdrive detonation wave formed by the detonation source attenuates to half the detonation velocity of CJ, the propagation radius must not be less than a full detonation cell size. This article conducts in-depth research on the direct initiation process of acetylene/oxygen mixture detonation. The results obtained have essential value for developing and applying the detonation theory of acetylene fuel. At the same time, they have important practical significance for preventing gas fire and explosion accidents.(c) 2023 The Combustion Institute. Published by Elsevier Inc. All rights reserved.