Intensification mechanisms of the lean hydrogen-air combustion via addition of suspended micro-droplets of water

Numerical Modeling of Combustion and Detonation in Aqueous Foams

“…Rather coarse droplets of ∼140 µm diameter are scattered in space with an average distance of ∼200 µm, which corresponds to the regime of flame propagation under the permanent effect of excitation of the short-wavelength perturbations by droplets and intensification of the instability growth. The same phenomenon was recently described in detail in [11]. As a result, the flame acceleration proceeds in the same way, independent of the geometry of the reactor.…”

“…Herewith, the average diameter of droplets is equal to the size of the plateau borders, which are about 0.7d b . Close conditions where the flame interacts with an array of equally spaced droplets were considered recently in [11]. In that paper, it was shown that the droplets affect the flame surface and cause excitation of the hydrodynamic instability development.…”

“…Thus, for example, in [10], the integral self-similar solution for the acceleration of the freely propagating flame is obtained based on the local dynamics of the flame subjected to the hydrodynamic instability. In a recent paper [11], the collective effect of water droplets suspended in a hydrogen-air mixture on the local flame dynamics and related flame intensification is studied. The local effects driving the evolution of the flame in the foamed emulsions and microfoams are still unresolved.…”

Localized water mist method enabling superior premixed hydrogen-methane-air deflagration mitigation in semi-confined space

“…However, the acceleration effect of water mist particles mainly manifests as the wrinkling of the flame surface induced by these particles, leading to an increase in flame surface area and thus accelerating the flame [49]. Additionally, in the preheating region, water mist particles that do not evaporate completely in time create a series of small obstacles [50]. As the flame passes through the gaps between these obstacles, it gets entrained and curled in the wake flow, interacting with turbulence, causing flame fragmentation, which further promotes the acceleration of the flame [51].…”

Combustion Characteristics of Methane-Air Mixtures in Millimeter-Scale Systems With a Cavity Structure: An Experimental and Numerical Study

“…Flame stabilization criteria are even more important when the system operates under small-scale conditions (Wan and Zhao, 2020b;Yakovenko and Kiverin, 2021). It would be especially desirable for combustion systems operating under such conditions to have flame stabilizers that would be highly resistant to external flow field dynamics and perturbations.…”