Numerical study of the influence of particle reaction and radiative heat transfer on the flame velocity of gas/nanoparticles hybrid mixtures

A one-dimensional model was developed to determine the flame velocity of a gas mixture explosion through a two-phase media containing nanoparticles. The mass and energy balances, which take into account a semi-global reaction mechanism with 10 reactions for methane and one carbon nanoparticles combustion, were solved by the finite volume method. The flame propagation model shows a good agreement with commercial software (Premix) to estimate the final temperature, the mass fraction of burnt gases and the flame velocity. For methane/carbon black nanoparticles hybrid mixtures, the numerical model evidences that the insertion of 10 μm particles (agglomerates diameter) does not influence significantly the flame velocity. Nevertheless, if the particle diameter of the dispersed dust is equals to 75 nm (diameter of the primary particles), a considerable increase of 23% of the flame propagation velocity is obtained when only 6 g m−3 are added to the combustible mixture. Hence, the results of the numerical model suggest that the heat radiation contribution has a promoting effect on the flame propagation and it is consistent with the experimental increase on the explosion severity for some methane/carbon black hybrid mixtures.