Measurement of Visible and Near-Infrared Optical Properties of Soot Produced from Laminar Flames.
Measurement of Visible and Near-Infrared Optical
Properties of Soot Produced from Laminar Flames.
Zhu, J.; Choi, M. Y.; Mulholland, G. W.; Manzello, S.
L.; Gritzo, L. A.; Suo-Anttila, J.
Combustion Institute, Symposium (International) on
Combustion, 29th. Volume 29. Part 2. Proceedings.
July 21-26, 2002, Sapporo, Japan, Combustion Institute,
Pittsburgh, PA, 2367-2374 pp, 2002.
soot; laminar flames; optical properties; smoke;
This study describes the measurements of the
dimensionless extinction constant, Ke, of soot in the
visible and infrared spectrum using the NIST Large
Agglomerate Optics Facility (LAOF). Soot was produced
using a 11 mm i.d. laminar diffusion flames burner
fueled with acetylene and ethene. Light extinction
measurements were performed using light sources at 543.5
nm, 632.8 nm, 856 nm, 1314 nm, and 1565 nm. The mean
values of present measurements of Ke range from 7.95 to
10.0. These measurements represent the first
fuel-specific data available in the near-infrared
spectrum. The measured Ke values for all wavelengths are
significantly larger than values calculated using
reported values of the refractive index. For soot from
acetylene flames, the Ke values increased with
wavelength, whereas for soot from ethene flames, the Ke
values decreased slightly with wavelength. Transmission
electron microscopy and optical microscopy analyses were
used to analyze soot morphology and aerosol properties
to estimate the influences of beam shielding and light
scattering on the observed variations of Ke.