On the evolution of fuel droplet evaporation zone and its interaction with flame front in ignition of spray flames

Evolution of fuel droplet evaporation zone and its interaction with propagating flame front are studied in this work. A general theory is developed to describe the evolutions propagation speed, temperature, onset completion locations ignition spherical flames. The influences liquid mass loading, heat exchange coefficient (or rate) Lewis number on spray studied. Two regimes considered, that is, heterogeneous homogeneous flames, based mixture condition near front. results indicate trajectories considerably affected by energy addition. critical for successful fuel-rich a coincidence inner outer balls from igniting kernel flame. always exist mixtures, indicating failure events occur only purely gaseous mixture. droplets have limited effects minimum energy, which, however, increases monotonically number. Moreover, originates mixtures due initially dispersed spark. evaporative loss burned unburned zones flames also evaluated, show failed kernels, behind before first then decreases. generally increases, although non-monotonicity exists, when successfully ignited propagate outwardly. For ratio total one decreases as expands. loading affect evaporating zones.