The current work examines regimes of the hydrogen-oxygen flame propagationand ignition of mixtures heated by radiation emitted from the flame. Thegaseous phase is assumed to be transparent for the radiation, while thesuspended particles of the dust cloud ahead of the flame absorb and reemit theradiation. The radiant heat absorbed by the particles is then lost byconduction to the surrounding unreacted gaseous phase so that the gas phasetemperature lags that of the particles. The direct numerical simulations solvethe full system of two phase gas dynamic time-dependent equations with adetailed chemical kinetics for a plane flames propagating through a dust cloud.It is shown that depending on the spatial distribution of the dispersedparticles and on the value of radiation absorption length the consequence ofthe radiative preheating of the mixture ahead of the flame can be either theincrease of the flame velocity for uniformly dispersed particles or ignitioneither new deflagration or detonation ahead of the original flame via theZel'dovich gradient mechanism in the case of a layered particle-gas clouddeposits. In the latter case the ignited combustion regime depends on theradiation absorption length and correspondingly on the steepness of the formedtemperature gradient in the preignition zone that can be treated independentlyof the primary flame. The impact of radiation heat transfer in a particle-ladenflames is of paramount importance for better risk assessment and represents aroute for understanding of dust explosion origin.
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