  The present study is devoted to the detailed numerical analysis of the
combustion waves propagation through the lean hydrogen-air mixtures with
suspended micro-droplets of water. Considered gaseous mixtures are
characterized by a relatively low reactivity and so the intensity of the
combustion waves is moderate. Herewith, it is found that the flame can be
noticeably accelerated in the presence of suspended micro-droplets. In
particular, it is shown that the interaction between the flame front and the
droplets with a diameter larger than 25~$\mu$m results in the enhancement of
the flame instability that provides a substantial acceleration of the mixture
burn-out process. At increased number density of water droplets the combustion
proceeds in a similar way to the combustion within a porous medium, and similar
trends are observed such as the increase in flame speed and intensification of
the combustion process with the pressure increasing inside the confined vessel.
In such a way it can be concluded that the water should be atomized in a proper
way when attempting to use it as hydrogen explosion inhibitor. Otherwise, water
droplets could induce flame acceleration via the mechanisms distinguished in
this paper.
