Smoke yields from turbulent buoyant jet flames

Abstract

Simple correlations for smoke yield in turbulent buoyant jet flames with smoke-point laminar flame heights are proposed and validated by using experimental data for gaseous, liquid and solid fuels. The smoke yield (kg smoke/kg fuel) in turbulent flames was measured for conditions representing turbulent buoyant jet flames (i.e. high effective B-number for solid and liquid fuels) while the laminar smoke-point properties were measured in a standard apparatus for gaseous and liquid fuels and in a new apparatus for solid fuels. The experimental results show, in agreement with the theoretical considerations, that the smoke yield is inversely proportional to the smoke-point heat release rate and proportional to the stoichiometric ratio. The present correlation is not expected to be valid for halogenated components (such as PVC) because the presence of halogens would affect both the gaseous combustion and the soot formation path chemistry. Smoke yields can be predicted for geometries and turbulent conditions other than turbulent jet buoyant flames by means of turbulent combustion models carefully compared and validated with the present and/or other results.