Evolution of properties for aging soot in premixed flat flames studied by laser-induced incandescence and elastic light scattering
Författare
Summary, in English
A detailed study has been made of soot growth in two premixed flat ethylene/air flames, at I broken vertical bar = 2.1 and I broken vertical bar = 2.3, where focus has been on following the change in optical properties from nascent to more mature soot, and the importance of these properties for laser-induced incandescence (LII). A combination of two-color LII (2C-LII) and elastic light scattering was utilized for studies of soot absorption and sublimation for a range of laser fluences in a pump-probe experiment, and the experimental results were compared with LII model predictions. Both flames show similar trends, indicating that the soot becomes less transparent during the growth process until some level of maturity is reached at higher flame heights, where the measured properties reach almost constant values. A sublimation fluence threshold of similar to 0.14 J/cm(2) (at 1064 nm for a flame temperature around 1700 K) was evaluated for mature soot, corresponding to a sublimation temperature of similar to 3400 K. Soot peak temperatures from 2C-LII were evaluated both using a constant E(m) and a wavelength dependence for E(m) extracted from extinction measurements, leading to a discussion on how the sublimation temperature relates to the maturity of soot.
Avdelning/ar
Publiceringsår
2015
Språk
Engelska
Sidor
669-683
Publikation/Tidskrift/Serie
Applied Physics B
Volym
119
Issue
4
Dokumenttyp
Artikel i tidskrift
Förlag
Springer
Ämne
- Atom and Molecular Physics and Optics
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0946-2171