Initiation of Detonation of a Hydrogen-Air Mixture due to Injection of Chemically Inert Solid Particles

Injection of inert particles into a stoichiometric hydrogen-air mixture with velocities ranging from 0.1 to 1.0 of the Chapman-Jouguet detonation velocity is calculated. Resultant flow regimes are analyzed. It is found that an increase in the particle temperature leads to ignition of the mixture, while an increase in the particle velocity leads to detonation wave initiation. Critical conditions of detonation initiation in terms of the particle concentration, particle size, and injection velocity are determined. Various possible scenarios of detonation initiation are demonstrated, depending on the particle diameter and concentration, including regimes with multiple initiation sites. Flow charts are constructed in the plane of the parameters "injection velocity-temperature of particles of various sizes."