Pulsating propagation and extinction of hydrogen detonations in ultrafine water sprays

Pulsating detonation and extinction in stoichiometric hydrogen/oxygen/argon gas with water sprays are studied for the first time. Eulerian-Lagrangian method is employed, emphasis laid on characterization of unsteady phenomena evolutions chemical / flow structures pulsating propagation extinction. Three modes found: (1) propagation, (2) followed by extinction, (3) immediate For detonation, within one cycle, speeds distance between reaction front (RF) shock (SF) change periodically. The phenomenon originates from interactions dynamics, kinetics, droplet dynamics inside induction zone. Multiple pressure waves emanated RF which overtake intensify lead SF. An autoigniting spot arises shocked after contact surface. relative locations SF, RF, shock-frame sonic point, two-phase surface remain unchanged a but their distances have periodic variations. Moreover, featured continuously increased SF quickly reduced peaks, temperature, combustion heat release. decoupling leads to significantly increasing timescale mixture. hydrodynamic structure also changes considerably when occurs. predicted map illustrates that critical mass loading reduces size becomes smaller. It found same size, average speed monotonically decreases loading. However, frequency non-monotonic dependence under constant