Numerical modeling of the ignition of a liquid hydrocarbon layer by a radiant heat pulse

A gas-phase model of radiative ignition of a flammable liquid is developed, allowing for absorption of the radiant flux in the gas phase. Using motor fuels (gasoline and diesel fuel), as examples, we demonstrate numerically the decisive effect of the gas-phase absorption of radiation, which is more sizable for fuels with a lower boiling point. An analysis of experimental data on radiative ignition and of the integral absorption coefficients obtained for motor fuels shows that a description of the gas-phase absorption of radiation has to take into account the possibility of soot formation during the preignition period of low-temperature oxidation of the hydrocarbon-fuel vapor.