A phenomenological model of near-field fire entrainment

摘要: A phenomenological model of air entrainment into combusting regions axisymmetric fire plumes is developed and compared with some existing experimental data. The considers engulfment ambient a plume due to the action toroidal vortices that are formed periodically close source an fire. It shown diffusive rates towards wrinkled flame sheet representing turbulent diffusion severely underpredicts by at least two orders magnitude, suggesting large-scale primary mechanism entrainment. By describing process as periodic around vortex rings frequency formation passage these in plumes, it modeled gives good agreement experimentally determined or mass fluxes. This accounts for physical processes unsteady dynamics, including effects pulsations first time. predicts flux grow linearly height above be independent heat release visible region. predicted scaling respect diameter appears range suggested Overall, this new provides better foundation near-field plumes. methodology can extended predict other dominated flows, such pulsating buoyant non-reacting