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Title: Large eddy simulation and laser diagnostic studies on a low swirl stratified premixed flame

Journal Article · · Combustion and Flame
;  [1];  [2]; ; ;  [3]
  1. Department of Energy Sciences, Lund Institute of Technology, Box 118, 22100 Lund (Sweden)
  2. Division of Weapons and Protection, The Swedish Defense Research Agency - FOI, Stockholm (Sweden)
  3. Department of Combustion Physics, Lund Institute of Technology, Lund (Sweden)

This paper presents numerical simulations and laser diagnostic experiments of a swirling lean premixed methane/air flame with an aim to compare different Large Eddy Simulations (LES) models for reactive flows. An atmospheric-pressure laboratory swirl burner has been developed wherein lean premixed methane/air is injected in an unconfined low-speed flow of air. The flame is stabilized above the burner rim in a moderate swirl flow, triggering weak vortex breakdown in the downstream direction. Both stereoscopic (3-component) PIV and 2-component PIV are used to investigate the flow. Filtered Rayleigh scattering is used to examine the temperature field in the leading flame front. Acetone-Planar Laser Induced Fluorescence (PLIF) is applied to examine the fuel distribution. The experimental data are used to assess two different LES models; one based on level-set G-equation and flamelet chemistry, and the other based on finite rate chemistry with reduced kinetics. The two LES models treat the chemistry differently, which results in different predictions of the flame dynamic behavior and statistics. Yet, great similarity of flame structures was predicted by both models. The LES and experimental data reveal several intrinsic features of the low swirl flame such as the W-shape at the leading front, the highly wrinkled fronts in the shear layers, and the existence of extinction holes in the trailing edge of the flame. The effect of combustion models, the numerical solvers and boundary conditions on the flame and flow predictions was systematically examined. (author)

OSTI ID:
21116117
Journal Information:
Combustion and Flame, Vol. 155, Issue 3; Other Information: Elsevier Ltd. All rights reserved; ISSN 0010-2180
Country of Publication:
United States
Language:
English