Effects of water droplet breakup on hydrogen/air detonations

Two-dimensional numerical simulations with Eulerian-Lagrangian method are conducted to study the influence of fine water droplet breakup on detonation propagation in stoichiometric hydrogen/air mixture. General features of gas phase and water droplets are well captured. Numerical soot foils are used to characterize the influence of droplet breakup on the detonation wave, and the results confirm that droplet disintegration make propagation detonation wave more stable under the studied conditions. Analysis on unsteady detonation propagation process is performed with the evolutions of spatial distribution of interphase transfer rates (mass, energy, and momentum). The interactions between detonation wave and water droplets demonstrate that the breakup model have more pronounced influence on mass and energy transfer than the momentum transfer. Moreover, high interphase transfer rates of disintegration case are observed at the onset of detonation propagation, and they gradually decrease. It is concluded that inclusion of droplet breakup significantly alters propagation and two-phase coupling of the gaseous detonation in fine water mists.