Transmission of hydrogen detonation across a curtain of dilute inert particles

Abstract

Transmission of hydrogen detonation wave (DW) in an inert particle curtain is simulated using the EulerianLagrangian approach. A detailed chemical mechanism is used to predict the detonative combustion of a stoichiometric hydrogen-air mixture and parametric studies are conducted based on a two-dimensional computational domain. A detonation map of propagation and extinction corresponding to various particle sizes, concentrations, and curtain thicknesses is plotted. It is shown that the critical curtain thickness decreases considerably when the particle concentration is less than the critical value. The effects of curtain thickness on the trajectories of peak pressure, shock front speed, and heat release rate are examined. Three propagation modes of the DW in particle curtain are found: detonation transmission, partial extinction and detonation re-initiation, as well as detonation extinction. The first two modes are analyzed with the evolutions of shock frontal structures and chemical explosive mode. The chemical explosive mode analysis confirms that a detonation re-initiation event is caused by a re-initiation point with high pressure and explosive propensity, resulting from transverse shock focusing. The influence of particle dimeter/concentration, and curtain thickness on the DW are also examined with peak pressure trajectories, shock speed, and interphase exchange rates of energy and momentum. In addition, small variations of the curtain thickness will affect the short-term behaviors of detonation development, but the long-term DW behaviors are negligibly affected. Furthermore, the evolutions of curtain morphologies are analyzed by the particle velocity, volume fraction, Stokes drag and Archimedes force. This analysis confirms the importance of drag force in influencing the curtain morphologies. Different curtain evolution regimes are found: quasi-stationary regime, shrinkage regime, constant-thickness regime, and expansion regime. Finally, the influences of the curtain thickness on the characteristic time of curtain evolutions are studied. It is found that all characteristic time become smaller when the curtain thickness increases.