Numerical Study on Re-Initiation of Detonation Propagating through Double Slits in a Planar Channel

摘要: For the safety of flammable gas transports and handling, suppressing the detonation wave is an important demand for the industry related to flammable gas handling. In particular, one way of detonation quenching is diffraction. Sudden expansions during the detonation propagation decrease the temperature and contribute to reducing reaction rates and separating the shock wave and reaction front. According to Mitrovanov and Soloukhin [1], the critical diameter for the detonation extinction is 13𝜆 for a circular tube and 10𝜆 for a planar channel, where 𝜆 is the equilibrium transverse wave spacing. Despite the decoupling of shock and reaction fronts due to diffraction, detonation waves still can be re-initiated once a high-energy source exists downstream such as Mach reflection [2-4]. Ohyagi et al.[5, 6] show experimentally that diffracted two shock waves from double slits also re-initiates the detonation wave. Moreover, they suggested that re-initiation distance and re-initiation mechanisms can be correlated with non-dimensional distance, where 𝑤 is the width of slits. The 𝑤/𝜆 ratio greater than unity was a favor for shock-shock re-initiation, which means at least one cell emerges at the slit. If 𝑤/𝜆 is smaller than unity, diffracted shock-shock interaction fails to produce the detonation wave, and shock-wall or reflected shock-shock interaction can be the next candidates of detonation re-initiation. However, detailed processes of shock-shock re-initiation are still questions and need to be investigated to understand the detonation re-initiation fully.In the present study, numerical simulations on a stoichiometric hydrogen-oxygen detonation reinitiation process of …