The effects of opposed flow velocity and radiative heat losses on the flame spreading over thermally thin fuels

Abstract A model was developed of flame spreading over thermally thin fuels in this paper, in which gaseous and solid surface radiative heat losses are included and the solid density at burnout exists as a parameter. The calculated results show that a peak value of flame spreading rate is reached when the opposed flow velocity is increased to a critical value, after which the flame spreading rate decreases monotonically as the opposed flow velocity is increased further. The radiative heat losses are determined as the cause of the above flame spreading characteristics by comparing the results of non-radiative model with that of fuU-radiative model. As another characteristics of microgravity flame spreading, the density at burnout in the quiescent microgravity is much greater than the counterpart in the normal gravity, which is caused by the cooling effect of radiative heat loss on the gas and the fuel surface near and at the burnout.