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Large Eddy Simulations of a piloted lean premix jet flame using finite-rate chemistry

Duwig, Christophe LU ; Nogenmyr, Karl-Johan; Chan, Cheong-ki and Dunn, Matthew J. (2011) In Combustion Theory and Modelling 15(4). p.537-568
Abstract
A Large Eddy Simulation (LES) model capable of accurately representing finite-rate chemistry effects in turbulent premixed combustion is presented. The LES computations use finite-rate chemistry and implicit LES combustion modelling to simulate an experimentally well-documented lean-premixed jet flame stabilized by a stoichiometric pilot. The validity of the implicit LES assumption is discussed and criteria are expressed in terms of subgrid scale Damkohler and Karlovitz numbers. Simulation results are compared to experimental data for velocity, temperature and species mass fractions of CH4, CO and OH. The simulation results highlight the validity and capability of the present approach for the flame and in general the combustion regime... (More)
A Large Eddy Simulation (LES) model capable of accurately representing finite-rate chemistry effects in turbulent premixed combustion is presented. The LES computations use finite-rate chemistry and implicit LES combustion modelling to simulate an experimentally well-documented lean-premixed jet flame stabilized by a stoichiometric pilot. The validity of the implicit LES assumption is discussed and criteria are expressed in terms of subgrid scale Damkohler and Karlovitz numbers. Simulation results are compared to experimental data for velocity, temperature and species mass fractions of CH4, CO and OH. The simulation results highlight the validity and capability of the present approach for the flame and in general the combustion regime examined. A sensitivity analysis to the choice of the finite-rate chemistry mechanism is reported, this analysis indicates that the one and two-step global reaction mechanisms evaluated fail to capture the reaction layer with sufficient accuracy, while a 20-species skeletal mechanism reproduces the experimental observations accurately including the key finite-rate chemistry indicators CO and OH. The LES results are shown to be grid insensitive and that the grid resolution within the bounds examined is far less important compared to the sensitivity of the finite-rate chemistry representation. The results are analyzed in terms of the flame dynamics and it is shown that intense small scale mixing (high Karlovitz number) between the pilot and the jet is an important mechanism for the stabilization of the flame. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
implicit LES, combustion modelling, finite-rate chemistry, turbulent, premixed combustion, LES validation
in
Combustion Theory and Modelling
volume
15
issue
4
pages
537 - 568
publisher
Taylor & Francis
external identifiers
  • wos:000295682100005
  • scopus:79960607555
ISSN
1364-7830
DOI
10.1080/13647830.2010.548531
language
English
LU publication?
yes
id
057386d5-dbc9-4293-ac1e-15def45a57d8 (old id 2179511)
date added to LUP
2011-10-25 11:35:42
date last changed
2017-11-05 03:25:46
@article{057386d5-dbc9-4293-ac1e-15def45a57d8,
  abstract     = {A Large Eddy Simulation (LES) model capable of accurately representing finite-rate chemistry effects in turbulent premixed combustion is presented. The LES computations use finite-rate chemistry and implicit LES combustion modelling to simulate an experimentally well-documented lean-premixed jet flame stabilized by a stoichiometric pilot. The validity of the implicit LES assumption is discussed and criteria are expressed in terms of subgrid scale Damkohler and Karlovitz numbers. Simulation results are compared to experimental data for velocity, temperature and species mass fractions of CH4, CO and OH. The simulation results highlight the validity and capability of the present approach for the flame and in general the combustion regime examined. A sensitivity analysis to the choice of the finite-rate chemistry mechanism is reported, this analysis indicates that the one and two-step global reaction mechanisms evaluated fail to capture the reaction layer with sufficient accuracy, while a 20-species skeletal mechanism reproduces the experimental observations accurately including the key finite-rate chemistry indicators CO and OH. The LES results are shown to be grid insensitive and that the grid resolution within the bounds examined is far less important compared to the sensitivity of the finite-rate chemistry representation. The results are analyzed in terms of the flame dynamics and it is shown that intense small scale mixing (high Karlovitz number) between the pilot and the jet is an important mechanism for the stabilization of the flame.},
  author       = {Duwig, Christophe and Nogenmyr, Karl-Johan and Chan, Cheong-ki and Dunn, Matthew J.},
  issn         = {1364-7830},
  keyword      = {implicit LES,combustion modelling,finite-rate chemistry,turbulent,premixed combustion,LES validation},
  language     = {eng},
  number       = {4},
  pages        = {537--568},
  publisher    = {Taylor & Francis},
  series       = {Combustion Theory and Modelling},
  title        = {Large Eddy Simulations of a piloted lean premix jet flame using finite-rate chemistry},
  url          = {http://dx.doi.org/10.1080/13647830.2010.548531},
  volume       = {15},
  year         = {2011},
}