  In this study we examine influence of the radiation heat transfer on the
combustion regimes in the mixture, formed by suspension of fine inert particles
in hydrogen gas. The gaseous phase is assumed to be transparent for the thermal
radiation, while the radiant heat absorbed by the particles is then lost by
conduction to the surrounding gas. The particles and gas ahead of the flame is
assumed to be heated by radiation from the original flame. It is shown that the
maximum temperature increase due to the radiation preheating becomes larger for
a flame with lower velocity. For a flame with small enough velocity temperature
of the radiation preheating may exceed the crossover temperature, so that the
radiation heat transfer may become a dominant mechanism of the flame
propagation. In the case of non-uniform distribution of particles, the
temperature gradient formed due to the radiation preheating can initiate either
deflagration or detonation ahead of the original flame via the Zel'dovich's
gradient mechanism. The initiated combustion regime ignited in the preheat zone
ahead of the flame depends on the radiation absorption length and on the
steepness of the formed temperature gradient. Scenario of the detonation
triggering via the temperature gradient mechanism formed due to the radiation
preheating is plausible explanation of the transition to detonation in
Supernovae Type Ia explosion.
