Dynamics of the fire plume

The author reviews progress made in understanding and predicting the dynamics of fire plumes and suggests areas for further study. Turbulant plumes, axisymmetric in the mean, are considered, from the far–field, weakly buoyant to the near–flame, strongly bouyant elevations, into the flaming region. Developments are traced to the present capabilities of predicting plume diameter, temperature, and velocity practically down to the flame level, air entrainment rates along the entire plume, flame heights, flame pulsation frequencies, flame deflections in wind, and plume reach in density–stratified space. Some recent research relative to behaviour of mass fires (such as ‘nuclear winter’ fires) is reviewed, a combustion mode which appears to offer many research opportunities. Certain areas are identified which can benefit from future research. These include effects of in–depth combustion, the near–source region of fires with low flame–height–to–diameter ratio, flame pulsations, flame bending and trailing in wind, plume air entrainment in ambients not free of disturbances, and certain disparities between measurements of plumes from flaming sources and plumes from discharge of bouyant gas.