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Large eddy simulation of vortex breakdown/flame interaction

Duwig, Christophe LU and Fuchs, Laszlo LU (2007) In Physics of Fluids 19(7).
Abstract
The dynamics of a swirl-stabilized premixed flame is studied using large eddy simulation (LES). A filtered flamelet model is used to account for the subgrid combustion. The model provides a consistent and robust reaction-diffusion expression for simulating the propagation of turbulent premixed flames correctly. The numerical results were found to be relatively insensitive to small changes in the inflow boundary conditions and to the numerical mesh employed. Furthermore, the results were found to agree well with the available experimental data both for velocity and scalar fields. In addition, unsteady flame features [i.e., precessing vortex core (PVC)] were identified and compared with experimental data. The agreement between LES results... (More)
The dynamics of a swirl-stabilized premixed flame is studied using large eddy simulation (LES). A filtered flamelet model is used to account for the subgrid combustion. The model provides a consistent and robust reaction-diffusion expression for simulating the propagation of turbulent premixed flames correctly. The numerical results were found to be relatively insensitive to small changes in the inflow boundary conditions and to the numerical mesh employed. Furthermore, the results were found to agree well with the available experimental data both for velocity and scalar fields. In addition, unsteady flame features [i.e., precessing vortex core (PVC)] were identified and compared with experimental data. The agreement between LES results and experimental data, in terms of flame dynamics, was also good. Increasing swirl did not affect the flame strongly but a decrease of swirl number was shown to change the flame shape and suppress the PVC. The PVC and flame dynamics were studied using proper orthogonal decomposition (POD) allowing us to identify and isolate the PVC from smaller-scale turbulence. The POD results indicate that the PVC corresponds to a helical wave consisting of two counter-rotating helices. A dynamical reduced model was also derived do describe the flame response to the PVC. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physics of Fluids
volume
19
issue
7
publisher
American Institute of Physics
external identifiers
  • wos:000248486100033
  • scopus:34547797309
ISSN
1070-6631
DOI
10.1063/1.2749812
language
English
LU publication?
yes
id
1bca6a44-5103-4cba-9ca7-2c7091dc8a89 (old id 657003)
date added to LUP
2007-12-06 11:25:14
date last changed
2017-09-17 05:06:00
@article{1bca6a44-5103-4cba-9ca7-2c7091dc8a89,
  abstract     = {The dynamics of a swirl-stabilized premixed flame is studied using large eddy simulation (LES). A filtered flamelet model is used to account for the subgrid combustion. The model provides a consistent and robust reaction-diffusion expression for simulating the propagation of turbulent premixed flames correctly. The numerical results were found to be relatively insensitive to small changes in the inflow boundary conditions and to the numerical mesh employed. Furthermore, the results were found to agree well with the available experimental data both for velocity and scalar fields. In addition, unsteady flame features [i.e., precessing vortex core (PVC)] were identified and compared with experimental data. The agreement between LES results and experimental data, in terms of flame dynamics, was also good. Increasing swirl did not affect the flame strongly but a decrease of swirl number was shown to change the flame shape and suppress the PVC. The PVC and flame dynamics were studied using proper orthogonal decomposition (POD) allowing us to identify and isolate the PVC from smaller-scale turbulence. The POD results indicate that the PVC corresponds to a helical wave consisting of two counter-rotating helices. A dynamical reduced model was also derived do describe the flame response to the PVC.},
  author       = {Duwig, Christophe and Fuchs, Laszlo},
  issn         = {1070-6631},
  language     = {eng},
  number       = {7},
  publisher    = {American Institute of Physics},
  series       = {Physics of Fluids},
  title        = {Large eddy simulation of vortex breakdown/flame interaction},
  url          = {http://dx.doi.org/10.1063/1.2749812},
  volume       = {19},
  year         = {2007},
}