GENERAL ASYMPTOTIC FORMULATION FOR SPRAY DIFFUSIONFLAMES INCLUDING INTERPHASE MOMENTUM AND HEATTRANSFER

摘要

An extension of a new general asymptotic formulation is given for laminar spraydiffusion flames including hitherto neglected inter-phase momentum and heattransfer. The formulation is not restricted to any specific geometric flame front shape.The multi-size spray of fuel droplets is permitted to evaporate at a finite rate. Generalmatching conditions are given across the front at which appreciable evaporationbegins and across the flame front. A solution strategy is outlined under circumstancesin which the Stokes number of the droplets in the spray is a small parameter that canbe exploited for developing a perturbation solution. Finally, an application of thetheory is made to the problem of a counterflow spray diffusion flame for which thedroplets are in dynamic and thermal disequilibrium with their surroundings. Howeverthey evaporate in a steep front thereby enabling effects of inter-phase heat transfer tobe compactly isolated.