Effects of aggregate morphology and size on laser-induced incandescence and scattering from black carbon (mature soot)
Abstract
For this study, we have used a Single-Particle Soot Photometer (SP2) to measure time-resolved laser-induced incandescence (LII) and laser scatter from combustion-generated mature soot with a fractal dimension of 1.88 extracted from a burner. We have also made measurements on restructured mature-soot particles with a fractal dimension of 2.3–2.4. We reproduced the LII and laser-scatter temporal profiles with an energy- and mass-balance model, which accounted for heating of particles passed through a CW-laser beam over laser–particle interaction times of ~10 μs. The results demonstrate a strong influence of aggregate size and morphology on LII and scattering signals. Conductive cooling competes with absorptive heating on these time scales; the effects are reduced with increasing aggregate size and fractal dimension. These effects can lead to a significant delay in the onset of the LII signal and may explain an apparent low bias in the SP2 measurements for small particle sizes, particularly for fresh, mature soot. In addition, the results reveal significant perturbations to the measured scattering signal from LII interference and suggest rapid expansion of the aggregates during sublimation.
- Authors:
- Publication Date:
- Research Org.:
- Sandia National Lab. (SNL-CA), Livermore, CA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division; USDOE National Nuclear Security Administration (NNSA)
- OSTI Identifier:
- 1244114
- Alternate Identifier(s):
- OSTI ID: 1214605; OSTI ID: 1236242; OSTI ID: 1265197; OSTI ID: 1310312; OSTI ID: 1310313
- Report Number(s):
- SAND-2015-0193J; SAND2015-6102J; SAND-2015-6102J
Journal ID: ISSN 0021-8502; S0021850215001020; PII: S0021850215001020
- Grant/Contract Number:
- AC04-94AL85000
- Resource Type:
- Published Article
- Journal Name:
- Journal of Aerosol Science
- Additional Journal Information:
- Journal Name: Journal of Aerosol Science Journal Volume: 88 Journal Issue: C; Journal ID: ISSN 0021-8502
- Publisher:
- Elsevier
- Country of Publication:
- United Kingdom
- Language:
- English
- Subject:
- 77 NANOSCIENCE AND NANOTECHNOLOGY; 54 ENVIRONMENTAL SCIENCES; Soot; Black carbon; LII; Scattering; SP2; Morphology; soot; black carbon; scattering; morphology; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE
Citation Formats
Bambha, Ray P., and Michelsen, Hope A. Effects of aggregate morphology and size on laser-induced incandescence and scattering from black carbon (mature soot). United Kingdom: N. p., 2015.
Web. doi:10.1016/j.jaerosci.2015.06.006.
Bambha, Ray P., & Michelsen, Hope A. Effects of aggregate morphology and size on laser-induced incandescence and scattering from black carbon (mature soot). United Kingdom. https://doi.org/10.1016/j.jaerosci.2015.06.006
Bambha, Ray P., and Michelsen, Hope A. Thu .
"Effects of aggregate morphology and size on laser-induced incandescence and scattering from black carbon (mature soot)". United Kingdom. https://doi.org/10.1016/j.jaerosci.2015.06.006.
@article{osti_1244114,
title = {Effects of aggregate morphology and size on laser-induced incandescence and scattering from black carbon (mature soot)},
author = {Bambha, Ray P. and Michelsen, Hope A.},
abstractNote = {For this study, we have used a Single-Particle Soot Photometer (SP2) to measure time-resolved laser-induced incandescence (LII) and laser scatter from combustion-generated mature soot with a fractal dimension of 1.88 extracted from a burner. We have also made measurements on restructured mature-soot particles with a fractal dimension of 2.3–2.4. We reproduced the LII and laser-scatter temporal profiles with an energy- and mass-balance model, which accounted for heating of particles passed through a CW-laser beam over laser–particle interaction times of ~10 μs. The results demonstrate a strong influence of aggregate size and morphology on LII and scattering signals. Conductive cooling competes with absorptive heating on these time scales; the effects are reduced with increasing aggregate size and fractal dimension. These effects can lead to a significant delay in the onset of the LII signal and may explain an apparent low bias in the SP2 measurements for small particle sizes, particularly for fresh, mature soot. In addition, the results reveal significant perturbations to the measured scattering signal from LII interference and suggest rapid expansion of the aggregates during sublimation.},
doi = {10.1016/j.jaerosci.2015.06.006},
journal = {Journal of Aerosol Science},
number = C,
volume = 88,
place = {United Kingdom},
year = {Thu Oct 01 00:00:00 EDT 2015},
month = {Thu Oct 01 00:00:00 EDT 2015}
}
https://doi.org/10.1016/j.jaerosci.2015.06.006
Web of Science