Methane explosions are common accidents in different applications, such as coal mines, metal mines, and natural gas pipelines. They may induce severe casualties and infrastructure damage. However, studies on micro structure of methane detonations are still very limited and hence the underlying controlling mechanism is not clear hitherto. In this study, used supercomputers and detailed chemical reaction mechanisms. And two-dimensional simulations with Eulerian-Lagrangian approach are carried out to study methane detonation propagation. The governing equations of gas and liquid phases are solved with RYrhoCentralFoam, which is developed based on the fully compressible non-reacting flow solver rhoCentralFoam in OpenFOAM 6.0. Detailed chemical mechanism is used for methane combustion. Moreover, unsteady response of methane detonation is studied. General features of gas phase and detailed detonation frontal structures are well captured. Incident detonations are discussed, about the evolutions of frontal structure and detonation propagation speed. Results for methaneair mixtures reveal that upon collision of two triple points a pair of forward and backward facing jets is formed. The drastic growth of the forward jet found to have profound role in re-acceleration of the detonation wave at the end of a detonation cell cycle. For irregular detonations, the transverse waves found to have substantial role in propagation mechanism of such detonations. In regular detonations, the lead shock ignites all the gases passing through it, hence, the transverse waves and hydrodynamic instabilities do not play crucial role in propagation mechanism of such regular detonations. In addition, the mechanism of methane detonation was analyzed in detail, including the changes of various components. The research results have a reference for understanding the mechanism of methane explosion and the prevention the explosion.

methane explosion,microstructure characterization,reaction mechanism,unsteady response