Atomization and Sprays, Vol.30, No.12, 895-911, 2020
AN IMPROVED MODEL FOR INVESTIGATING THE EFFECT OF SPRAY POLYDISPERSITY ON LAMINAR PREMIXED SPRAY FLAME IGNITION
An improved simplified theory of polydisperse spray flame ignition is presented for the case of a semi-infinite homogeneous region of air and fuel droplets subjected to heat flux by an infinite slab. Our previous models used a basic assumption that the evaporation commences simultaneously for all droplets at a given prespecified evaporation temperature, irrespective of the size of the droplets. In view of the fact that the range of heat-up times of different size droplets may be nonnegligible, a new description of and solution for the polydisperse spray is presented, which accounts for the disparity in onset of evaporation. The governing equations are solved, and results are offered to illustrate how possible ignition scenarios resulting from the spray polydispersity are altered due to the more accurate description of the basic physics.