Advanced

Numerical and experimental study of flame propagation and quenching of lean premixed turbulent low swirl flames at different Reynolds numbers

Carlsson, Henning LU ; Nordström, Emil LU ; Bohlin, Alexis LU ; Wu, Yajing LU ; Zhou, Bo LU ; Li, Zhongshan LU ; Aldén, Marcus LU ; Bengtsson, Per-Erik LU and Bai, Xue-Song LU (2015) In Combustion and Flame 162(6). p.2582-2591
Abstract
This paper presents a joint experimental and large eddy simulation (LES) study of lean premixed low swirl stabilized methane/air flames at different Reynolds numbers (Re similar to 20,000-100,000). The aims are to investigate the sensitivity of the structures and dynamics of low swirl flames to the inflow boundary conditions and to evaluate the capability of an LES flamelet model in predicting the stabilization and local extinction of the flames. Chemiluminescence measurements are carried out for Re - 20,000-50,000 and further detailed oxygen concentration and temperature fields are measured using rotational coherent anti-Stokes Raman spectroscopy (RCARS) for Re - 20,000 and 30,000 along the centerline of the burner and at various radial... (More)
This paper presents a joint experimental and large eddy simulation (LES) study of lean premixed low swirl stabilized methane/air flames at different Reynolds numbers (Re similar to 20,000-100,000). The aims are to investigate the sensitivity of the structures and dynamics of low swirl flames to the inflow boundary conditions and to evaluate the capability of an LES flamelet model in predicting the stabilization and local extinction of the flames. Chemiluminescence measurements are carried out for Re - 20,000-50,000 and further detailed oxygen concentration and temperature fields are measured using rotational coherent anti-Stokes Raman spectroscopy (RCARS) for Re - 20,000 and 30,000 along the centerline of the burner and at various radial positions at different heights above the burner. The data are used first for validation of the combustion LES model employed in the numerical simulations, and then the RCARS and LES results are used to delineate the effect of ambient air entrainment on the flame structure at various burner exit velocities. A three-scalar flamelet model based on a level-set G-equation shows excellent predictions of the lift-off positions and the structures of the flames, including quenching at the trailing edge of the flame. The results show that the flame lift-off height varies only slightly when the burner exit velocity is increased, which is consistent with a shear-layer flame stabilization mechanism reported previously. The volume of the flame decreases substantially with increasing burner exit velocity at relatively low Reynolds numbers, as a result of flame quenching at the trailing edge of the flame caused by entrainment of the ambient air into the fuel/air stream and the flame itself. At high Reynolds numbers the flame structures become fairly self-similar with the flame volume nearly independent of the Reynolds number. (C) 2015 The Combustion Institute. Published by Elsevier Inc. All rights reserved. (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
Model validation, Large eddy simulation, Rotational coherent anti-Stokes, Raman spectroscopy, Thermometry, Low swirl flame sensitivity
in
Combustion and Flame
volume
162
issue
6
pages
2582 - 2591
publisher
Elsevier
external identifiers
  • wos:000360592600024
  • scopus:84937763879
ISSN
0010-2180
DOI
10.1016/j.combustflame.2015.03.007
language
English
LU publication?
yes
id
2b94259d-0273-454f-8c37-42edbd40263a (old id 8080551)
date added to LUP
2015-10-26 15:12:24
date last changed
2017-10-22 03:59:53
@article{2b94259d-0273-454f-8c37-42edbd40263a,
  abstract     = {This paper presents a joint experimental and large eddy simulation (LES) study of lean premixed low swirl stabilized methane/air flames at different Reynolds numbers (Re similar to 20,000-100,000). The aims are to investigate the sensitivity of the structures and dynamics of low swirl flames to the inflow boundary conditions and to evaluate the capability of an LES flamelet model in predicting the stabilization and local extinction of the flames. Chemiluminescence measurements are carried out for Re - 20,000-50,000 and further detailed oxygen concentration and temperature fields are measured using rotational coherent anti-Stokes Raman spectroscopy (RCARS) for Re - 20,000 and 30,000 along the centerline of the burner and at various radial positions at different heights above the burner. The data are used first for validation of the combustion LES model employed in the numerical simulations, and then the RCARS and LES results are used to delineate the effect of ambient air entrainment on the flame structure at various burner exit velocities. A three-scalar flamelet model based on a level-set G-equation shows excellent predictions of the lift-off positions and the structures of the flames, including quenching at the trailing edge of the flame. The results show that the flame lift-off height varies only slightly when the burner exit velocity is increased, which is consistent with a shear-layer flame stabilization mechanism reported previously. The volume of the flame decreases substantially with increasing burner exit velocity at relatively low Reynolds numbers, as a result of flame quenching at the trailing edge of the flame caused by entrainment of the ambient air into the fuel/air stream and the flame itself. At high Reynolds numbers the flame structures become fairly self-similar with the flame volume nearly independent of the Reynolds number. (C) 2015 The Combustion Institute. Published by Elsevier Inc. All rights reserved.},
  author       = {Carlsson, Henning and Nordström, Emil and Bohlin, Alexis and Wu, Yajing and Zhou, Bo and Li, Zhongshan and Aldén, Marcus and Bengtsson, Per-Erik and Bai, Xue-Song},
  issn         = {0010-2180},
  keyword      = {Model validation,Large eddy simulation,Rotational coherent anti-Stokes,Raman spectroscopy,Thermometry,Low swirl flame sensitivity},
  language     = {eng},
  number       = {6},
  pages        = {2582--2591},
  publisher    = {Elsevier},
  series       = {Combustion and Flame},
  title        = {Numerical and experimental study of flame propagation and quenching of lean premixed turbulent low swirl flames at different Reynolds numbers},
  url          = {http://dx.doi.org/10.1016/j.combustflame.2015.03.007},
  volume       = {162},
  year         = {2015},
}