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Flamelet modelling of soot formation in diffusion flames

Dederichs, Anne Simone LU (2004)
Abstract
In this work the steady and unsteady flamelet models have been applied to soot formation in laminar and turbulent diffusion flames. The aim was to study how different model parameters affect soot formation in diffusion flames. It was shown that certain assumptions are more crucial in laminar diffusion flames than in turbulent ones. The soot formation in turbulent diffusion flames is more sensitive to the surface dependence of the particle and altering the active site parameter, than in laminar flames. This is due to the fact that the flame is laminar and the turbulent mixing, which supplies the particle with radicals, does not affect the process. The active site parameter decreases in the absence of radicals. The modelling of complex... (More)
In this work the steady and unsteady flamelet models have been applied to soot formation in laminar and turbulent diffusion flames. The aim was to study how different model parameters affect soot formation in diffusion flames. It was shown that certain assumptions are more crucial in laminar diffusion flames than in turbulent ones. The soot formation in turbulent diffusion flames is more sensitive to the surface dependence of the particle and altering the active site parameter, than in laminar flames. This is due to the fact that the flame is laminar and the turbulent mixing, which supplies the particle with radicals, does not affect the process. The active site parameter decreases in the absence of radicals. The modelling of complex diffusivity of all species is more relevant in laminar diffusion flames than in turbulent diffusion flames. All transient effects investigated in this work were shown to affect soot formation, which is itself transient. It was shown that these effects are more relevant for laminar fames than for turbulent flames. The steady flamelet model allows the inclusion of many transient processes and thereby loses in accuracy compared with the unsteady model. Finally, the process of the formation of agglomerates was included in the unsteady model and it was shown that the soot volume fraction is affected when this process is considered. (Less)
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author
opponent
  • Professor Moss, Barrie, Cranfield University, UK
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Environmental technology, Emissions, Pollution, pollution control, Miljöteknik, kontroll av utsläpp
pages
174 pages
publisher
Fire Safety Engineering
defense location
Room V:A, V-building, John Ericssons väg 1, Lund Institute of Technology.
defense date
2004-06-17 10:15
external identifiers
  • other:ISRN: LUTVDG/TVBB--1031--SE
ISSN
1102-8246
ISBN
ISBN 91-628-6127-1
language
English
LU publication?
yes
id
9b743a25-6914-4c81-9271-21ed221807f1 (old id 21764)
date added to LUP
2007-05-28 14:34:04
date last changed
2016-09-19 08:44:53
@phdthesis{9b743a25-6914-4c81-9271-21ed221807f1,
  abstract     = {In this work the steady and unsteady flamelet models have been applied to soot formation in laminar and turbulent diffusion flames. The aim was to study how different model parameters affect soot formation in diffusion flames. It was shown that certain assumptions are more crucial in laminar diffusion flames than in turbulent ones. The soot formation in turbulent diffusion flames is more sensitive to the surface dependence of the particle and altering the active site parameter, than in laminar flames. This is due to the fact that the flame is laminar and the turbulent mixing, which supplies the particle with radicals, does not affect the process. The active site parameter decreases in the absence of radicals. The modelling of complex diffusivity of all species is more relevant in laminar diffusion flames than in turbulent diffusion flames. All transient effects investigated in this work were shown to affect soot formation, which is itself transient. It was shown that these effects are more relevant for laminar fames than for turbulent flames. The steady flamelet model allows the inclusion of many transient processes and thereby loses in accuracy compared with the unsteady model. Finally, the process of the formation of agglomerates was included in the unsteady model and it was shown that the soot volume fraction is affected when this process is considered.},
  author       = {Dederichs, Anne Simone},
  isbn         = {ISBN 91-628-6127-1},
  issn         = {1102-8246},
  keyword      = {Environmental technology,Emissions,Pollution,pollution control,Miljöteknik,kontroll av utsläpp},
  language     = {eng},
  pages        = {174},
  publisher    = {Fire Safety Engineering},
  school       = {Lund University},
  title        = {Flamelet modelling of soot formation in diffusion flames},
  year         = {2004},
}