Measurement of the Optical Extinction Coefficients of Post-Flame Soot in the Infrared.
Measurement of the Optical Extinction Coefficients of
Post-Flame Soot in the Infrared.
(326 K)
Widmann, J. F.; Yang, J. C.; Manzello, S. L.;
Mulholland, G. W.
Fire Suppression and Detection Research Application
Symposium. Research and Practice: Bridging the Gap.
Proceedings. Fire Protection Research Foundation.
January 22-24, 2003, Orlando, FL, 449-468 pp, 2003.
Combustion and Flame, Vol. 134, No. 1/2, 119-129, July
2003.
Keywords:
fire suppression; fire detection; fire research; fire
safety; fire protection; soot; infrared radiation;
radiative heat transfer; smoke; radiative absorption
Abstract:
The optical extinction coefficients of post-flame soot
have been measured in the wavelength range 2.8
micrometers to 4.1 micrometers. A laminar diffusion
burner was combined with an infrared spectrograph and
gravimetric measurements to determine the mass specific
extinction coefficient, sigma, and the dimensionless
extinction coefficient, Ke. Using ethene gas as the
fuel, the burner was operated at four global equivalence
ratios (phi = 0.8, 1.0, 2.0, and 3.0) to examine the
effect of the fuel-air ratio on the extinction
coefficient. The extinction coefficient was found to
decrease with increasing values of the global
equivalence ratio for phi = 1.0, 2.0, and 3.0. The
results for phi = 0.8 and phi = 1.0 were in agreement to
within the uncertainty of the measurements. Measurements
were obtained using propane gas as the fuel (phi = 1.0)
and resulted in extinction coefficients equivalent to
those of ethene.
