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Effects of flame stretch and wrinkling on CO formation in turbulent premixed combustion

Nilsson, Per LU and Bai, Xue-Song LU (2002) Twenty-Ninth International Symposium on Combustion Hokkaido University Sapporo Japan In Proceedings of the Combustion Institute 29(2). p.1873-1879
Abstract
This paper presents an investigation of CO formation in a lean premixed propane/air turbulent flame in an afterburner configuration. A previous experiment showed that a high amount of CO was formed in the mean turbulent flame brush. To explain the high CO concentration in the flame zone, the effects of flame stretch and flame wrinkling are studied, based on an ensemble averaged laminar flamelet library approach. It is shown that the flame stretch decreases the laminar burning velocity by 20% under the studied flame conditions, and the stretched flamelet model predicts the non-equilibrium CO concentration in the postflame zone. However, the high CO concentration in the mean flame brush cannot be predicted by a stretched flamelet library... (More)
This paper presents an investigation of CO formation in a lean premixed propane/air turbulent flame in an afterburner configuration. A previous experiment showed that a high amount of CO was formed in the mean turbulent flame brush. To explain the high CO concentration in the flame zone, the effects of flame stretch and flame wrinkling are studied, based on an ensemble averaged laminar flamelet library approach. It is shown that the flame stretch decreases the laminar burning velocity by 20% under the studied flame conditions, and the stretched flamelet model predicts the non-equilibrium CO concentration in the postflame zone. However, the high CO concentration in the mean flame brush cannot be predicted by a stretched flamelet library model alone. A flamelet model accounting for wrinkled flamelets in the mean turbulent flame brush, and the effect of flame stretch (mainly strain rate), is tested. The model is based on a level-set G-equation for the mean position of the turbulent flame brush and an ensemble average of strained laminar flamelet libraries. A comparison of the numerical results with the experimental data and a previous translating flamelet model clearly shows that the wrinkled flamelet model predicts the intermediate species, such as CO, more accurately. The major species such as O-2 and CO2, as well as temperature, are found to be not sensitive to the flame wrinkling. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Flame stretch
in
Proceedings of the Combustion Institute
volume
29
issue
2
pages
1873 - 1879
publisher
Elsevier
conference name
Twenty-Ninth International Symposium on Combustion Hokkaido University Sapporo Japan
external identifiers
  • wos:000182866500054
ISSN
1873-2704
1540-7489
DOI
10.1016/S1540-7489(02)80227-9
language
English
LU publication?
yes
id
9d87ef68-15f6-418e-9d55-9569e44c989c (old id 310806)
date added to LUP
2007-11-28 12:41:12
date last changed
2016-09-23 15:15:28
@inproceedings{9d87ef68-15f6-418e-9d55-9569e44c989c,
  abstract     = {This paper presents an investigation of CO formation in a lean premixed propane/air turbulent flame in an afterburner configuration. A previous experiment showed that a high amount of CO was formed in the mean turbulent flame brush. To explain the high CO concentration in the flame zone, the effects of flame stretch and flame wrinkling are studied, based on an ensemble averaged laminar flamelet library approach. It is shown that the flame stretch decreases the laminar burning velocity by 20% under the studied flame conditions, and the stretched flamelet model predicts the non-equilibrium CO concentration in the postflame zone. However, the high CO concentration in the mean flame brush cannot be predicted by a stretched flamelet library model alone. A flamelet model accounting for wrinkled flamelets in the mean turbulent flame brush, and the effect of flame stretch (mainly strain rate), is tested. The model is based on a level-set G-equation for the mean position of the turbulent flame brush and an ensemble average of strained laminar flamelet libraries. A comparison of the numerical results with the experimental data and a previous translating flamelet model clearly shows that the wrinkled flamelet model predicts the intermediate species, such as CO, more accurately. The major species such as O-2 and CO2, as well as temperature, are found to be not sensitive to the flame wrinkling.},
  author       = {Nilsson, Per and Bai, Xue-Song},
  booktitle    = {Proceedings of the Combustion Institute},
  issn         = {1873-2704},
  keyword      = {Flame stretch},
  language     = {eng},
  number       = {2},
  pages        = {1873--1879},
  publisher    = {Elsevier},
  title        = {Effects of flame stretch and wrinkling on CO formation in turbulent premixed combustion},
  url          = {http://dx.doi.org/10.1016/S1540-7489(02)80227-9},
  volume       = {29},
  year         = {2002},
}