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Numerical studies of flame extinction and re-ignition behaviors in a novel, ultra-lean, non-premixed model GT burner using LES-ESF method

Yu, Senbin LU ; Sadanandan, Rajesh and Bai, Xue Song LU (2019) In Fuel
Abstract

The flame dynamics in a novel, ultra-lean non-premixed model gas turbine (GT) burner flame was numerically studied using large eddy simulation (LES) coupled with probability density function (PDF) based on the Euler stochastic field (ESF) method. One non-reacting case and three reacting cases with global equivalence ratio ϕglob=1.0,0.6,0.3 were simulated. Comparison of mean flow fields and OH distributions between numerical and experimental results was conducted. Flame dynamics including flame stabilization, structures and transitions of combustion modes were investigated. The simulation results were in close agreements with the experimental measurements showing the capability of PDF-ESF LES model in predicting the flame... (More)

The flame dynamics in a novel, ultra-lean non-premixed model gas turbine (GT) burner flame was numerically studied using large eddy simulation (LES) coupled with probability density function (PDF) based on the Euler stochastic field (ESF) method. One non-reacting case and three reacting cases with global equivalence ratio ϕglob=1.0,0.6,0.3 were simulated. Comparison of mean flow fields and OH distributions between numerical and experimental results was conducted. Flame dynamics including flame stabilization, structures and transitions of combustion modes were investigated. The simulation results were in close agreements with the experimental measurements showing the capability of PDF-ESF LES model in predicting the flame behaviors. At higher ϕglob, the fuel jet velocity was higher, which yielded higher scalar dissipation rate, χ, near the burner exit, leading to local extinction and flame lifted-off. In the extinction region, a series of relatively low to medium temperature reactions were active, providing favorable conditions for re-ignition downstream where χ is lower than the critical scalar dissipation rate for flame extinction, χcrt. In addition, with ϕglob decreasing, the flame height decreased due to a smaller jet velocity and χ, and thus the mechanism of flame stabilization changed from the swirl-stabilized to the bluff-body stabilized.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Bluff-body, Extinction, LES, PDF-ESF, Re-ignition, Swirl
in
Fuel
article number
116617
publisher
Elsevier
external identifiers
  • scopus:85075386866
ISSN
0016-2361
DOI
10.1016/j.fuel.2019.116617
language
English
LU publication?
yes
id
8b6d6b15-329a-4018-9835-1f3fd1ea8c1a
date added to LUP
2019-12-09 12:47:03
date last changed
2020-01-13 02:35:13
@article{8b6d6b15-329a-4018-9835-1f3fd1ea8c1a,
  abstract     = {<p>The flame dynamics in a novel, ultra-lean non-premixed model gas turbine (GT) burner flame was numerically studied using large eddy simulation (LES) coupled with probability density function (PDF) based on the Euler stochastic field (ESF) method. One non-reacting case and three reacting cases with global equivalence ratio ϕ<sub>glob</sub>=1.0,0.6,0.3 were simulated. Comparison of mean flow fields and OH distributions between numerical and experimental results was conducted. Flame dynamics including flame stabilization, structures and transitions of combustion modes were investigated. The simulation results were in close agreements with the experimental measurements showing the capability of PDF-ESF LES model in predicting the flame behaviors. At higher ϕ<sub>glob</sub>, the fuel jet velocity was higher, which yielded higher scalar dissipation rate, χ, near the burner exit, leading to local extinction and flame lifted-off. In the extinction region, a series of relatively low to medium temperature reactions were active, providing favorable conditions for re-ignition downstream where χ is lower than the critical scalar dissipation rate for flame extinction, χ<sub>crt</sub>. In addition, with ϕ<sub>glob</sub> decreasing, the flame height decreased due to a smaller jet velocity and χ, and thus the mechanism of flame stabilization changed from the swirl-stabilized to the bluff-body stabilized.</p>},
  author       = {Yu, Senbin and Sadanandan, Rajesh and Bai, Xue Song},
  issn         = {0016-2361},
  language     = {eng},
  publisher    = {Elsevier},
  series       = {Fuel},
  title        = {Numerical studies of flame extinction and re-ignition behaviors in a novel, ultra-lean, non-premixed model GT burner using LES-ESF method},
  url          = {http://dx.doi.org/10.1016/j.fuel.2019.116617},
  doi          = {10.1016/j.fuel.2019.116617},
  year         = {2019},
}