Soot Formation in Unstrained Diffusion Flames
Författare
Summary, in English
The formation of soot particles has been investigated in CH4/O-2 diffusion flames using a unique burner design, which allows the creation of a nearly unstrained planar reaction sheet. Spatially resolved soot volume fractions were obtained using laser-induced incandescence. These soot measurements and the sooting limits were obtained as a function of bulk flow across the flame and mixture strength. Samples were collected using thermophoretic sampling and analyzed using electron microscopy, revealing a broad range of microstructures including particles with unusually large primary diameters and carbon nanotubes. A theoretical model is presented, which confirms that under certain conditions the 1D nature of the flow field of the burner and the strong adverse temperature gradient on the fuel side of the flame result in the soot particles being held in place by thermophoretic forces and allowed to grow for very long time periods. Some of these so-called super aggregates reached sizes of tens of microns and became visible to the naked eye in the soot layer.
Avdelning/ar
Publiceringsår
2015
Språk
Engelska
Sidor
577-593
Publikation/Tidskrift/Serie
Combustion Science and Technology
Volym
187
Issue
4
Dokumenttyp
Artikel i tidskrift
Förlag
Taylor & Francis
Ämne
- Atom and Molecular Physics and Optics
Nyckelord
- Diffusion flame
- Laser-induced incandescence
- Soot
- Super aggregate
- Thermophoresis
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1563-521X