- Author
- Chao, Y. H. C. | Fernandez-Pello, A. C.
- Title
- Concurrent Horizontal Flame Spread: The Combined Effect of Oxidizer Flow Velocity, Turbulence and Oxygen Concentration.
- Coporate
- California Univ., Berkeley
- Journal
- Combustion Science and Technology, Vol. 110-111, 19-51, 1995
- Sponsor
- National Institute of Standards and Technology, Gaithersburg, MD
- Contract
- NIST-GRANT-60NANB1D1174
- Keywords
- flame spread | velocity | turbulence | oxygen concentration | flame length | heat flux | experiments | flame spread rate | equations | surface heat | pyrolysis temperature | exhaust gases | soot | soot formation
- Identifiers
- controlling mechanisms; surface heat flux; derviation of the flame to pyrolysis length ratio; derivation of the non-dimensional heat flux
- Abstract
- Experiments have been conducted to study the transport and chemical kinetics mechanisms controlling the spread of flames over the surface of a thick solid fuel in an oxidizing gas flow moving in the direction of flame propagation (concurrent or flow assisted flame spread). In the experiments, the solid fuel (PMMA) is unchanged, but the oxidizer gas flow velocity, turbulence intensity and oxygen concentration, are systematically varied to determine their effect on the flame spread process. This is done by measuring the rate of flame spread, flame length, surface heat flux, exhaust gas temperature, products of combustion and soot. The results of the experiments show that the combined effect of flow velocity, turbulence intensity, and oxygen concentration has a complex influence on the flame spread process. The observed variation of the flame rate with the flow parameters appears to be due to a strong influence of these parameters on the flame temperature and length, and on the heat flux from the flame to the solid fuel surface. Measurements of the combustion products provide further information about how the flow parameters affect the flame length and surface heat flux.